diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ce9c08221e..ba64552973 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -13,6 +13,20 @@ instance, Boolean, Integer, String), but also allow them to hold either the
 typed value, or a String that can be converted to their typed value. For example,
 an Integer can contain 3 or '3'. This changed an update to the xblock library.
 
+LMS: Courses whose id matches a regex in the COURSES_WITH_UNSAFE_CODE Django
+setting now run entirely outside the Python sandbox.
+
+Blades: Video Alpha bug fix for speed changing to 1.0 in Firefox.
+
+Blades: Additional event tracking added to Video Alpha: fullscreen switch, show/hide
+captions.
+
+CMS: Allow editors to delete uploaded files/assets
+
+XModules: `XModuleDescriptor.__init__` and `XModule.__init__` dropped the
+`location` parameter (and added it as a field), and renamed `system` to `runtime`,
+to accord more closely to `XBlock.__init__`
+
 LMS: Some errors handling Non-ASCII data in XML courses have been fixed.
 
 LMS: Add page-load tracking using segment-io (if SEGMENT_IO_LMS_KEY and
@@ -35,7 +49,7 @@ student.
 Blades: Staff debug info is now accessible for Graphical Slider Tool problems.
 
 Blades: For Video Alpha the events ready, play, pause, seek, and speed change
-are logged on the server (in the logs). 
+are logged on the server (in the logs).
 
 Common: Developers can now have private Django settings files.
 
@@ -56,7 +70,7 @@ Common: The "duplicate email" error message is more informative.
 
 Studio: Component metadata settings editor.
 
-Studio: Autoplay is disabled (only in Studio).
+Studio: Autoplay for Video Alpha is disabled (only in Studio).
 
 Studio: Single-click creation for video and discussion components.
 
diff --git a/cms/CHANGELOG.md b/cms/CHANGELOG.md
deleted file mode 100644
index d21d08d23c..0000000000
--- a/cms/CHANGELOG.md
+++ /dev/null
@@ -1,21 +0,0 @@
-Instructions
-============
-For each pull request, add one or more lines to the bottom of the change list. When
-code is released to production, change the `Upcoming` entry to todays date, and add
-a new block at the bottom of the file.
-
-    Upcoming
-    --------
-
-Change log entries should be targeted at end users. A good place to start is the
-user story that instigated the pull request.
-
-
-Changes
-=======
-
-Upcoming
---------
-* Fix: Deleting last component in a unit does not work
-* Fix: Unit name is editable when a unit is public
-* Fix: Visual feedback inconsistent when saving a unit name change
diff --git a/cms/djangoapps/contentstore/features/advanced-settings.py b/cms/djangoapps/contentstore/features/advanced-settings.py
index 049103db27..4995f3505d 100644
--- a/cms/djangoapps/contentstore/features/advanced-settings.py
+++ b/cms/djangoapps/contentstore/features/advanced-settings.py
@@ -3,11 +3,7 @@
 
 from lettuce import world, step
 from nose.tools import assert_false, assert_equal, assert_regexp_matches
-
-"""
-http://selenium.googlecode.com/svn/trunk/docs/api/py/webdriver/selenium.webdriver.common.keys.html
-"""
-from selenium.webdriver.common.keys import Keys
+from common import type_in_codemirror
 
 KEY_CSS = '.key input.policy-key'
 VALUE_CSS = 'textarea.json'
@@ -37,13 +33,7 @@ def press_the_notification_button(step, name):
 
 @step(u'I edit the value of a policy key$')
 def edit_the_value_of_a_policy_key(step):
-    """
-    It is hard to figure out how to get into the CodeMirror
-    area, so cheat and do it from the policy key field :)
-    """
-    world.css_find(".CodeMirror")[get_index_of(DISPLAY_NAME_KEY)].click()
-    g = world.css_find("div.CodeMirror.CodeMirror-focused > div > textarea")
-    g._element.send_keys(Keys.ARROW_LEFT, ' ', 'X')
+    type_in_codemirror(get_index_of(DISPLAY_NAME_KEY), 'X')
 
 
 @step(u'I edit the value of a policy key and save$')
@@ -132,13 +122,5 @@ def change_display_name_value(step, new_value):
 
 
 def change_value(step, key, new_value):
-    index = get_index_of(key)
-    world.css_find(".CodeMirror")[index].click()
-    g = world.css_find("div.CodeMirror.CodeMirror-focused > div > textarea")
-    current_value = world.css_find(VALUE_CSS)[index].value
-    g._element.send_keys(Keys.CONTROL + Keys.END)
-    for count in range(len(current_value)):
-        g._element.send_keys(Keys.END, Keys.BACK_SPACE)
-        # Must delete "" before typing the JSON value
-    g._element.send_keys(Keys.END, Keys.BACK_SPACE, Keys.BACK_SPACE, new_value)
+    type_in_codemirror(get_index_of(key), new_value)
     press_the_notification_button(step, "Save")
diff --git a/cms/djangoapps/contentstore/features/common.py b/cms/djangoapps/contentstore/features/common.py
index fec1b90040..e7187e83d8 100644
--- a/cms/djangoapps/contentstore/features/common.py
+++ b/cms/djangoapps/contentstore/features/common.py
@@ -179,3 +179,14 @@ def shows_captions(step, show_captions):
         assert world.css_find('.video')[0].has_class('closed')
     else:
         assert world.is_css_not_present('.video.closed')
+
+
+def type_in_codemirror(index, text):
+    world.css_click(".CodeMirror", index=index)
+    g = world.css_find("div.CodeMirror.CodeMirror-focused > div > textarea")
+    if world.is_mac():
+        g._element.send_keys(Keys.COMMAND + 'a')
+    else:
+        g._element.send_keys(Keys.CONTROL + 'a')
+    g._element.send_keys(Keys.DELETE)
+    g._element.send_keys(text)
diff --git a/cms/djangoapps/contentstore/features/problem-editor.feature b/cms/djangoapps/contentstore/features/problem-editor.feature
index bde350d8a3..cc1d766d2e 100644
--- a/cms/djangoapps/contentstore/features/problem-editor.feature
+++ b/cms/djangoapps/contentstore/features/problem-editor.feature
@@ -3,65 +3,71 @@ Feature: Problem Editor
 
   Scenario: User can view metadata
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I see five alphabetized settings and their expected values
     And Edit High Level Source is not visible
 
   Scenario: User can modify String values
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can modify the display name
     And my display name change is persisted on save
 
   Scenario: User can specify special characters in String values
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can specify special characters in the display name
     And my special characters and persisted on save
 
   Scenario: User can revert display name to unset
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can revert the display name to unset
     And my display name is unset on save
 
   Scenario: User can select values in a Select
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can select Per Student for Randomization
     And my change to randomization is persisted
     And I can revert to the default value for randomization
 
   Scenario: User can modify float input values
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can set the weight to "3.5"
     And my change to weight is persisted
     And I can revert to the default value of unset for weight
 
   Scenario: User cannot type letters in float number field
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then if I set the weight to "abc", it remains unset
 
   Scenario: User cannot type decimal values integer number field
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then if I set the max attempts to "2.34", it displays initially as "234", and is persisted as "234"
 
   Scenario: User cannot type out of range values in an integer number field
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then if I set the max attempts to "-3", it displays initially as "-3", and is persisted as "0"
 
   Scenario: Settings changes are not saved on Cancel
     Given I have created a Blank Common Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then I can set the weight to "3.5"
     And I can modify the display name
     Then If I press Cancel my changes are not persisted
 
   Scenario: Edit High Level source is available for LaTeX problem
     Given I have created a LaTeX Problem
-    And I edit and select Settings
+    When I edit and select Settings
     Then Edit High Level Source is visible
+
+  Scenario: High Level source is persisted for LaTeX problem (bug STUD-280)
+    Given I have created a LaTeX Problem
+    When I edit and compile the High Level Source
+    Then my change to the High Level Source is persisted
+    And when I view the High Level Source I see my changes
diff --git a/cms/djangoapps/contentstore/features/problem-editor.py b/cms/djangoapps/contentstore/features/problem-editor.py
index 7679128beb..8691a6772e 100644
--- a/cms/djangoapps/contentstore/features/problem-editor.py
+++ b/cms/djangoapps/contentstore/features/problem-editor.py
@@ -3,6 +3,7 @@
 
 from lettuce import world, step
 from nose.tools import assert_equal
+from common import type_in_codemirror
 
 DISPLAY_NAME = "Display Name"
 MAXIMUM_ATTEMPTS = "Maximum Attempts"
@@ -135,12 +136,12 @@ def set_the_max_attempts(step, max_attempts_set, max_attempts_displayed, max_att
 
 @step('Edit High Level Source is not visible')
 def edit_high_level_source_not_visible(step):
-    verify_high_level_source(step, False)
+    verify_high_level_source_links(step, False)
 
 
 @step('Edit High Level Source is visible')
-def edit_high_level_source_visible(step):
-    verify_high_level_source(step, True)
+def edit_high_level_source_links_visible(step):
+    verify_high_level_source_links(step, True)
 
 
 @step('If I press Cancel my changes are not persisted')
@@ -153,13 +154,33 @@ def cancel_does_not_save_changes(step):
 @step('I have created a LaTeX Problem')
 def create_latex_problem(step):
     world.click_new_component_button(step, '.large-problem-icon')
-    # Go to advanced tab (waiting for the tab to be visible)
-    world.css_find('#ui-id-2')
+    # Go to advanced tab.
     world.css_click('#ui-id-2')
     world.click_component_from_menu("i4x://edx/templates/problem/Problem_Written_in_LaTeX", '.xmodule_CapaModule')
 
 
-def verify_high_level_source(step, visible):
+@step('I edit and compile the High Level Source')
+def edit_latex_source(step):
+    open_high_level_source()
+    type_in_codemirror(1, "hi")
+    world.css_click('.hls-compile')
+
+
+@step('my change to the High Level Source is persisted')
+def high_level_source_persisted(step):
+    def verify_text(driver):
+        return world.css_find('.problem').text == 'hi'
+
+    world.wait_for(verify_text)
+
+
+@step('I view the High Level Source I see my changes')
+def high_level_source_in_editor(step):
+    open_high_level_source()
+    assert_equal('hi', world.css_find('.source-edit-box').value)
+
+
+def verify_high_level_source_links(step, visible):
     assert_equal(visible, world.is_css_present('.launch-latex-compiler'))
     world.cancel_component(step)
     assert_equal(visible, world.is_css_present('.upload-button'))
@@ -187,3 +208,8 @@ def verify_unset_display_name():
 
 def set_weight(weight):
     world.get_setting_entry(PROBLEM_WEIGHT).find_by_css('.setting-input')[0].fill(weight)
+
+
+def open_high_level_source():
+    world.css_click('a.edit-button')
+    world.css_click('.launch-latex-compiler > a')
diff --git a/cms/djangoapps/contentstore/management/commands/empty_asset_trashcan.py b/cms/djangoapps/contentstore/management/commands/empty_asset_trashcan.py
new file mode 100644
index 0000000000..9af3277a2b
--- /dev/null
+++ b/cms/djangoapps/contentstore/management/commands/empty_asset_trashcan.py
@@ -0,0 +1,25 @@
+from django.core.management.base import BaseCommand, CommandError
+from xmodule.course_module import CourseDescriptor
+from xmodule.contentstore.utils import empty_asset_trashcan
+from xmodule.modulestore.django import modulestore
+from .prompt import query_yes_no
+
+
+class Command(BaseCommand):
+    help = '''Empty the trashcan. Can pass an optional course_id to limit the damage.'''
+
+    def handle(self, *args, **options):
+        if len(args) != 1 and len(args) != 0:
+            raise CommandError("empty_asset_trashcan requires one or no arguments: |<location>|")
+
+        locs = []
+
+        if len(args) == 1:
+            locs.append(CourseDescriptor.id_to_location(args[0]))
+        else:
+            courses = modulestore('direct').get_courses()
+            for course in courses:
+                locs.append(course.location)
+
+        if query_yes_no("Emptying trashcan. Confirm?", default="no"):
+            empty_asset_trashcan(locs)
diff --git a/cms/djangoapps/contentstore/management/commands/restore_asset_from_trashcan.py b/cms/djangoapps/contentstore/management/commands/restore_asset_from_trashcan.py
new file mode 100644
index 0000000000..6770bfaf44
--- /dev/null
+++ b/cms/djangoapps/contentstore/management/commands/restore_asset_from_trashcan.py
@@ -0,0 +1,13 @@
+from django.core.management.base import BaseCommand, CommandError
+from xmodule.contentstore.utils import restore_asset_from_trashcan
+
+
+class Command(BaseCommand):
+    help = '''Restore a deleted asset from the trashcan back to it's original course'''
+
+    def handle(self, *args, **options):
+        if len(args) != 1 and len(args) != 0:
+            raise CommandError("restore_asset_from_trashcan requires one argument: <location>")
+
+        restore_asset_from_trashcan(args[0])
+
diff --git a/cms/djangoapps/contentstore/tests/test_contentstore.py b/cms/djangoapps/contentstore/tests/test_contentstore.py
index 03449fc22f..9346d2189d 100644
--- a/cms/djangoapps/contentstore/tests/test_contentstore.py
+++ b/cms/djangoapps/contentstore/tests/test_contentstore.py
@@ -28,6 +28,8 @@ from xmodule.templates import update_templates
 from xmodule.modulestore.xml_exporter import export_to_xml
 from xmodule.modulestore.xml_importer import import_from_xml, perform_xlint
 from xmodule.modulestore.inheritance import own_metadata
+from xmodule.contentstore.content import StaticContent
+from xmodule.contentstore.utils import restore_asset_from_trashcan, empty_asset_trashcan
 
 from xmodule.capa_module import CapaDescriptor
 from xmodule.course_module import CourseDescriptor
@@ -35,6 +37,7 @@ from xmodule.seq_module import SequenceDescriptor
 from xmodule.modulestore.exceptions import ItemNotFoundError
 
 from contentstore.views.component import ADVANCED_COMPONENT_TYPES
+from xmodule.exceptions import NotFoundError
 
 from django_comment_common.utils import are_permissions_roles_seeded
 from xmodule.exceptions import InvalidVersionError
@@ -382,6 +385,159 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
         course = module_store.get_item(source_location)
         self.assertFalse(course.hide_progress_tab)
 
+    def test_asset_import(self):
+        '''
+        This test validates that an image asset is imported and a thumbnail was generated for a .gif
+        '''
+        content_store = contentstore()
+
+        module_store = modulestore('direct')
+        import_from_xml(module_store, 'common/test/data/', ['full'], static_content_store=content_store)
+
+        course_location = CourseDescriptor.id_to_location('edX/full/6.002_Spring_2012')
+        course = module_store.get_item(course_location)
+
+        self.assertIsNotNone(course)
+
+        # make sure we have some assets in our contentstore
+        all_assets = content_store.get_all_content_for_course(course_location)
+        self.assertGreater(len(all_assets), 0)
+
+        # make sure we have some thumbnails in our contentstore
+        all_thumbnails = content_store.get_all_content_thumbnails_for_course(course_location)
+
+        #
+        # cdodge: temporarily comment out assertion on thumbnails because many environments
+        # will not have the jpeg converter installed and this test will fail
+        #
+        #
+        # self.assertGreater(len(all_thumbnails), 0)
+
+        content = None
+        try:
+            location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+            content = content_store.find(location)
+        except NotFoundError:
+            pass
+
+        self.assertIsNotNone(content)
+
+        #
+        # cdodge: temporarily comment out assertion on thumbnails because many environments
+        # will not have the jpeg converter installed and this test will fail
+        #
+        # self.assertIsNotNone(content.thumbnail_location)
+        #
+        # thumbnail = None
+        # try:
+        #    thumbnail = content_store.find(content.thumbnail_location)
+        # except:
+        #    pass
+        #
+        # self.assertIsNotNone(thumbnail)
+
+    def test_asset_delete_and_restore(self):
+        '''
+        This test will exercise the soft delete/restore functionality of the assets
+        '''
+        content_store = contentstore()
+        trash_store = contentstore('trashcan')
+        module_store = modulestore('direct')
+
+        import_from_xml(module_store, 'common/test/data/', ['full'], static_content_store=content_store)
+
+        # look up original (and thumbnail) in content store, should be there after import
+        location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+        content = content_store.find(location, throw_on_not_found=False)
+        thumbnail_location = content.thumbnail_location
+        self.assertIsNotNone(content)
+
+        #
+        # cdodge: temporarily comment out assertion on thumbnails because many environments
+        # will not have the jpeg converter installed and this test will fail
+        #
+        # self.assertIsNotNone(thumbnail_location)
+
+        # go through the website to do the delete, since the soft-delete logic is in the view
+
+        url = reverse('remove_asset', kwargs={'org': 'edX', 'course': 'full', 'name': '6.002_Spring_2012'})
+        resp = self.client.post(url, {'location': '/c4x/edX/full/asset/circuits_duality.gif'})
+        self.assertEqual(resp.status_code, 200)
+
+        asset_location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+
+        # now try to find it in store, but they should not be there any longer
+        content = content_store.find(asset_location, throw_on_not_found=False)
+        self.assertIsNone(content)
+
+        if thumbnail_location:
+            thumbnail = content_store.find(thumbnail_location, throw_on_not_found=False)
+            self.assertIsNone(thumbnail)
+
+        # now try to find it and the thumbnail in trashcan - should be in there
+        content = trash_store.find(asset_location, throw_on_not_found=False)
+        self.assertIsNotNone(content)
+
+        if thumbnail_location:
+            thumbnail = trash_store.find(thumbnail_location, throw_on_not_found=False)
+            self.assertIsNotNone(thumbnail)
+
+        # let's restore the asset
+        restore_asset_from_trashcan('/c4x/edX/full/asset/circuits_duality.gif')
+
+        # now try to find it in courseware store, and they should be back after restore
+        content = content_store.find(asset_location, throw_on_not_found=False)
+        self.assertIsNotNone(content)
+
+        if thumbnail_location:
+            thumbnail = content_store.find(thumbnail_location, throw_on_not_found=False)
+            self.assertIsNotNone(thumbnail)
+
+    def test_empty_trashcan(self):
+        '''
+        This test will exercise the empting of the asset trashcan
+        '''
+        content_store = contentstore()
+        trash_store = contentstore('trashcan')
+        module_store = modulestore('direct')
+
+        import_from_xml(module_store, 'common/test/data/', ['full'], static_content_store=content_store)
+
+        course_location = CourseDescriptor.id_to_location('edX/full/6.002_Spring_2012')
+
+        location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+        content = content_store.find(location, throw_on_not_found=False)
+        self.assertIsNotNone(content)
+
+        # go through the website to do the delete, since the soft-delete logic is in the view
+
+        url = reverse('remove_asset', kwargs={'org': 'edX', 'course': 'full', 'name': '6.002_Spring_2012'})
+        resp = self.client.post(url, {'location': '/c4x/edX/full/asset/circuits_duality.gif'})
+        self.assertEqual(resp.status_code, 200)
+
+        # make sure there's something in the trashcan
+        all_assets = trash_store.get_all_content_for_course(course_location)
+        self.assertGreater(len(all_assets), 0)
+
+        # make sure we have some thumbnails in our trashcan
+        all_thumbnails = trash_store.get_all_content_thumbnails_for_course(course_location)
+        #
+        # cdodge: temporarily comment out assertion on thumbnails because many environments
+        # will not have the jpeg converter installed and this test will fail
+        #
+        # self.assertGreater(len(all_thumbnails), 0)
+
+        # empty the trashcan
+        empty_asset_trashcan([course_location])
+
+        # make sure trashcan is empty
+        all_assets = trash_store.get_all_content_for_course(course_location)
+        self.assertEqual(len(all_assets), 0)
+
+
+        all_thumbnails = trash_store.get_all_content_thumbnails_for_course(course_location)
+        self.assertEqual(len(all_thumbnails), 0)
+
     def test_clone_course(self):
 
         course_data = {
diff --git a/cms/djangoapps/contentstore/views/assets.py b/cms/djangoapps/contentstore/views/assets.py
index 229788f24d..400013b59b 100644
--- a/cms/djangoapps/contentstore/views/assets.py
+++ b/cms/djangoapps/contentstore/views/assets.py
@@ -25,6 +25,8 @@ from xmodule.modulestore.django import modulestore
 from xmodule.modulestore import Location
 from xmodule.contentstore.content import StaticContent
 from xmodule.util.date_utils import get_default_time_display
+from xmodule.modulestore import InvalidLocationError
+from xmodule.exceptions import NotFoundError
 
 from ..utils import get_url_reverse
 from .access import get_location_and_verify_access
@@ -78,10 +80,17 @@ def asset_index(request, org, course, name):
         'active_tab': 'assets',
         'context_course': course_module,
         'assets': asset_display,
-        'upload_asset_callback_url': upload_asset_callback_url
+        'upload_asset_callback_url': upload_asset_callback_url,
+        'remove_asset_callback_url': reverse('remove_asset', kwargs={
+            'org': org,
+            'course': course,
+            'name': name
+        })
     })
 
 
+@login_required
+@ensure_csrf_cookie
 def upload_asset(request, org, course, coursename):
     '''
     cdodge: this method allows for POST uploading of files into the course asset library, which will
@@ -145,6 +154,57 @@ def upload_asset(request, org, course, coursename):
     return response
 
 
+@ensure_csrf_cookie
+@login_required
+def remove_asset(request, org, course, name):
+    '''
+    This method will perform a 'soft-delete' of an asset, which is basically to copy the asset from
+    the main GridFS collection and into a Trashcan
+    '''
+    get_location_and_verify_access(request, org, course, name)
+
+    location = request.POST['location']
+
+    # make sure the location is valid
+    try:
+        loc = StaticContent.get_location_from_path(location)
+    except InvalidLocationError:
+        # return a 'Bad Request' to browser as we have a malformed Location
+        response = HttpResponse()
+        response.status_code = 400
+        return response
+
+    # also make sure the item to delete actually exists
+    try:
+        content = contentstore().find(loc)
+    except NotFoundError:
+        response = HttpResponse()
+        response.status_code = 404
+        return response
+
+    # ok, save the content into the trashcan
+    contentstore('trashcan').save(content)
+
+    # see if there is a thumbnail as well, if so move that as well
+    if content.thumbnail_location is not None:
+        try:
+            thumbnail_content = contentstore().find(content.thumbnail_location)
+            contentstore('trashcan').save(thumbnail_content)
+            # hard delete thumbnail from origin
+            contentstore().delete(thumbnail_content.get_id())
+            # remove from any caching
+            del_cached_content(thumbnail_content.location)
+        except:
+            pass  # OK if this is left dangling
+
+    # delete the original
+    contentstore().delete(content.get_id())
+    # remove from cache
+    del_cached_content(content.location)
+
+    return HttpResponse()
+
+
 @ensure_csrf_cookie
 @login_required
 def import_course(request, org, course, name):
diff --git a/cms/envs/aws.py b/cms/envs/aws.py
index 35b15fe6ba..a6d6e2f847 100644
--- a/cms/envs/aws.py
+++ b/cms/envs/aws.py
@@ -112,8 +112,11 @@ TIME_ZONE = ENV_TOKENS.get('TIME_ZONE', TIME_ZONE)
 for feature, value in ENV_TOKENS.get('MITX_FEATURES', {}).items():
     MITX_FEATURES[feature] = value
 
-# load segment.io key, provide a dummy if it does not exist
-SEGMENT_IO_KEY = ENV_TOKENS.get('SEGMENT_IO_KEY', '***REMOVED***')
+# If Segment.io key specified, load it and turn on Segment.io if the feature flag is set
+# Note that this is the Studio key. There is a separate key for the LMS.
+SEGMENT_IO_KEY = AUTH_TOKENS.get('SEGMENT_IO_KEY')
+if SEGMENT_IO_KEY:
+    MITX_FEATURES['SEGMENT_IO'] = ENV_TOKENS.get('SEGMENT_IO', False)
 
 LOGGING = get_logger_config(LOG_DIR,
                             logging_env=ENV_TOKENS['LOGGING_ENV'],
diff --git a/cms/envs/common.py b/cms/envs/common.py
index 5962cec340..8551a56c41 100644
--- a/cms/envs/common.py
+++ b/cms/envs/common.py
@@ -32,13 +32,23 @@ from path import path
 
 MITX_FEATURES = {
     'USE_DJANGO_PIPELINE': True,
+    
     'GITHUB_PUSH': False,
+    
     'ENABLE_DISCUSSION_SERVICE': False,
+    
     'AUTH_USE_MIT_CERTIFICATES': False,
-    'STUB_VIDEO_FOR_TESTING': False,  # do not display video when running automated acceptance tests
-    'STAFF_EMAIL': '',  # email address for staff (eg to request course creation)
+    
+    # do not display video when running automated acceptance tests
+    'STUB_VIDEO_FOR_TESTING': False,
+    
+    # email address for staff (eg to request course creation)
+    'STAFF_EMAIL': '',
+    
     'STUDIO_NPS_SURVEY': True,
-    'SEGMENT_IO': True,
+    
+    # Segment.io - must explicitly turn it on for production
+    'SEGMENT_IO': False,
 
     # Enable URL that shows information about the status of various services
     'ENABLE_SERVICE_STATUS': False,
@@ -228,7 +238,8 @@ PIPELINE_JS = {
         ) + ['js/hesitate.js', 'js/base.js',
              'js/models/feedback.js', 'js/views/feedback.js',
              'js/models/section.js', 'js/views/section.js',
-             'js/models/metadata_model.js', 'js/views/metadata_editor_view.js'],
+             'js/models/metadata_model.js', 'js/views/metadata_editor_view.js',
+             'js/views/assets.js'],
         'output_filename': 'js/cms-application.js',
         'test_order': 0
     },
diff --git a/cms/envs/dev.py b/cms/envs/dev.py
index cbe47a1fe1..6327d442d2 100644
--- a/cms/envs/dev.py
+++ b/cms/envs/dev.py
@@ -43,10 +43,15 @@ CONTENTSTORE = {
     'OPTIONS': {
         'host': 'localhost',
         'db': 'xcontent',
+    },
+    # allow for additional options that can be keyed on a name, e.g. 'trashcan'
+    'ADDITIONAL_OPTIONS': {
+        'trashcan': {
+            'bucket': 'trash_fs'
+        }
     }
 }
 
-
 DATABASES = {
     'default': {
         'ENGINE': 'django.db.backends.sqlite3',
@@ -163,8 +168,13 @@ MITX_FEATURES['STUDIO_NPS_SURVEY'] = False
 # Enable URL that shows information about the status of variuous services
 MITX_FEATURES['ENABLE_SERVICE_STATUS'] = True
 
-# segment-io key for dev
-SEGMENT_IO_KEY = 'mty8edrrsg'
+############################# SEGMENT-IO ##################################
+
+# If there's an environment variable set, grab it and turn on Segment.io
+# Note that this is the Studio key. There is a separate key for the LMS.
+SEGMENT_IO_KEY = os.environ.get('SEGMENT_IO_KEY')
+if SEGMENT_IO_KEY:
+    MITX_FEATURES['SEGMENT_IO'] = True
 
 
 #####################################################################
diff --git a/cms/envs/test.py b/cms/envs/test.py
index 1569d0a42d..954a553e10 100644
--- a/cms/envs/test.py
+++ b/cms/envs/test.py
@@ -70,7 +70,13 @@ CONTENTSTORE = {
     'ENGINE': 'xmodule.contentstore.mongo.MongoContentStore',
     'OPTIONS': {
         'host': 'localhost',
-        'db': 'xcontent',
+        'db': 'test_xmodule',
+    },
+    # allow for additional options that can be keyed on a name, e.g. 'trashcan'
+    'ADDITIONAL_OPTIONS': {
+        'trashcan': {
+            'bucket': 'trash_fs'
+        }
     }
 }
 
diff --git a/cms/static/coffee/src/views/module_edit.coffee b/cms/static/coffee/src/views/module_edit.coffee
index d0a76a6c15..5154591d6f 100644
--- a/cms/static/coffee/src/views/module_edit.coffee
+++ b/cms/static/coffee/src/views/module_edit.coffee
@@ -44,8 +44,17 @@ class CMS.Views.ModuleEdit extends Backbone.View
         [@metadataEditor.getDisplayName()])
       @$el.find('.component-name').html(title)
 
+  customMetadata: ->
+      # Hack to support metadata fields that aren't part of the metadata editor (ie, LaTeX high level source).
+      # Walk through the set of elements which have the 'data-metadata_name' attribute and
+      # build up an object to pass back to the server on the subsequent POST.
+      # Note that these values will always be sent back on POST, even if they did not actually change.
+      _metadata = {}
+      _metadata[$(el).data("metadata-name")] = el.value for el in $('[data-metadata-name]',  @$component_editor())
+      return _metadata
+
   changedMetadata: ->
-    return @metadataEditor.getModifiedMetadataValues()
+    return _.extend(@metadataEditor.getModifiedMetadataValues(), @customMetadata())
 
   cloneTemplate: (parent, template) ->
     $.post("/clone_item", {
diff --git a/cms/static/js/base.js b/cms/static/js/base.js
index c626fa1b3f..92a16b8417 100644
--- a/cms/static/js/base.js
+++ b/cms/static/js/base.js
@@ -32,8 +32,6 @@ $(document).ready(function() {
 
     $modal.bind('click', hideModal);
     $modalCover.bind('click', hideModal);
-    $('.uploads .upload-button').bind('click', showUploadModal);
-    $('.upload-modal .close-button').bind('click', hideModal);
 
     $body.on('click', '.embeddable-xml-input', function() {
         $(this).select();
@@ -145,8 +143,6 @@ $(document).ready(function() {
     $('.edit-section-start-cancel').bind('click', cancelSetSectionScheduleDate);
     $('.edit-section-start-save').bind('click', saveSetSectionScheduleDate);
 
-    $('.upload-modal .choose-file-button').bind('click', showFileSelectionMenu);
-
     $body.on('click', '.section-published-date .edit-button', editSectionPublishDate);
     $body.on('click', '.section-published-date .schedule-button', editSectionPublishDate);
     $body.on('click', '.edit-subsection-publish-settings .save-button', saveSetSectionScheduleDate);
@@ -398,73 +394,6 @@ function _deleteItem($el) {
     });
 }
 
-function showUploadModal(e) {
-    e.preventDefault();
-    $modal = $('.upload-modal').show();
-    $('.file-input').bind('change', startUpload);
-    $modalCover.show();
-}
-
-function showFileSelectionMenu(e) {
-    e.preventDefault();
-    $('.file-input').click();
-}
-
-function startUpload(e) {
-    var files = $('.file-input').get(0).files;
-    if (files.length === 0)
-        return;
-
-    $('.upload-modal h1').html(gettext('Uploading…'));
-    $('.upload-modal .file-name').html(files[0].name);
-    $('.upload-modal .file-chooser').ajaxSubmit({
-        beforeSend: resetUploadBar,
-        uploadProgress: showUploadFeedback,
-        complete: displayFinishedUpload
-    });
-    $('.upload-modal .choose-file-button').hide();
-    $('.upload-modal .progress-bar').removeClass('loaded').show();
-}
-
-function resetUploadBar() {
-    var percentVal = '0%';
-    $('.upload-modal .progress-fill').width(percentVal);
-    $('.upload-modal .progress-fill').html(percentVal);
-}
-
-function showUploadFeedback(event, position, total, percentComplete) {
-    var percentVal = percentComplete + '%';
-    $('.upload-modal .progress-fill').width(percentVal);
-    $('.upload-modal .progress-fill').html(percentVal);
-}
-
-function displayFinishedUpload(xhr) {
-    if (xhr.status = 200) {
-        markAsLoaded();
-    }
-
-    var resp = JSON.parse(xhr.responseText);
-    $('.upload-modal .embeddable-xml-input').val(xhr.getResponseHeader('asset_url'));
-    $('.upload-modal .embeddable').show();
-    $('.upload-modal .file-name').hide();
-    $('.upload-modal .progress-fill').html(resp.msg);
-    $('.upload-modal .choose-file-button').html(gettext('Load Another File')).show();
-    $('.upload-modal .progress-fill').width('100%');
-
-    // see if this id already exists, if so, then user must have updated an existing piece of content
-    $("tr[data-id='" + resp.url + "']").remove();
-
-    var template = $('#new-asset-element').html();
-    var html = Mustache.to_html(template, resp);
-    $('table > tbody').prepend(html);
-
-    analytics.track('Uploaded a File', {
-        'course': course_location_analytics,
-        'asset_url': resp.url
-    });
-
-}
-
 function markAsLoaded() {
     $('.upload-modal .copy-button').css('display', 'inline-block');
     $('.upload-modal .progress-bar').addClass('loaded');
diff --git a/cms/static/js/models/feedback.js b/cms/static/js/models/feedback.js
index 1f1ee57000..d57cffa779 100644
--- a/cms/static/js/models/feedback.js
+++ b/cms/static/js/models/feedback.js
@@ -42,6 +42,12 @@ CMS.Models.ErrorMessage = CMS.Models.SystemFeedback.extend({
     })
 });
 
+CMS.Models.ConfirmAssetDeleteMessage = CMS.Models.SystemFeedback.extend({
+    defaults: $.extend({}, CMS.Models.SystemFeedback.prototype.defaults, {
+        "intent": "warning"
+    })
+});
+
 CMS.Models.ConfirmationMessage = CMS.Models.SystemFeedback.extend({
     defaults: $.extend({}, CMS.Models.SystemFeedback.prototype.defaults, {
         "intent": "confirmation"
diff --git a/cms/static/js/views/assets.js b/cms/static/js/views/assets.js
new file mode 100644
index 0000000000..9eb521dcb6
--- /dev/null
+++ b/cms/static/js/views/assets.js
@@ -0,0 +1,128 @@
+$(document).ready(function() {
+    $('.uploads .upload-button').bind('click', showUploadModal);
+    $('.upload-modal .close-button').bind('click', hideModal);
+    $('.upload-modal .choose-file-button').bind('click', showFileSelectionMenu);
+    $('.remove-asset-button').bind('click', removeAsset);
+});
+
+function removeAsset(e){
+    e.preventDefault();
+
+    var that = this;
+    var msg = new CMS.Models.ConfirmAssetDeleteMessage({
+        title: gettext("Delete File Confirmation"),
+        message: gettext("Are you sure you wish to delete this item. It cannot be reversed!\n\nAlso any content that links/refers to this item will no longer work (e.g. broken images and/or links)"),
+        actions: {
+            primary: {
+                text: gettext("OK"),
+                click: function(view) {
+                    // call the back-end to actually remove the asset
+                    $.post(view.model.get('remove_asset_url'),
+                        { 'location': view.model.get('asset_location') },
+                        function() {
+                            // show the post-commit confirmation
+                            $(".wrapper-alert-confirmation").addClass("is-shown").attr('aria-hidden','false');
+                            view.model.get('row_to_remove').remove();
+                            analytics.track('Deleted Asset', {
+                                'course': course_location_analytics,
+                                'id': view.model.get('asset_location')
+                            });
+                        }
+                    );
+                    view.hide();
+                }
+            },
+            secondary: [{
+                text: gettext("Cancel"),
+                click: function(view) {
+                    view.hide();
+                }
+            }]
+        },
+        remove_asset_url: $('.asset-library').data('remove-asset-callback-url'),
+        asset_location: $(this).closest('tr').data('id'),
+        row_to_remove: $(this).closest('tr')
+    });
+
+    // workaround for now. We can't spawn multiple instances of the Prompt View
+    // so for now, a bit of hackery to just make sure we have a single instance
+    // note: confirm_delete_prompt is in asset_index.html
+    if (confirm_delete_prompt === null)
+        confirm_delete_prompt = new CMS.Views.Prompt({model: msg});
+    else
+    {
+        confirm_delete_prompt.model = msg;
+        confirm_delete_prompt.show();
+    }
+
+    return;
+}
+
+function showUploadModal(e) {
+    e.preventDefault();
+    $modal = $('.upload-modal').show();
+    $('.file-input').bind('change', startUpload);
+    $modalCover.show();
+}
+
+function showFileSelectionMenu(e) {
+    e.preventDefault();
+    $('.file-input').click();
+}
+
+function startUpload(e) {
+    var files = $('.file-input').get(0).files;
+    if (files.length === 0)
+        return;
+
+    $('.upload-modal h1').html(gettext('Uploading…'));
+    $('.upload-modal .file-name').html(files[0].name);
+    $('.upload-modal .file-chooser').ajaxSubmit({
+        beforeSend: resetUploadBar,
+        uploadProgress: showUploadFeedback,
+        complete: displayFinishedUpload
+    });
+    $('.upload-modal .choose-file-button').hide();
+    $('.upload-modal .progress-bar').removeClass('loaded').show();
+}
+
+function resetUploadBar() {
+    var percentVal = '0%';
+    $('.upload-modal .progress-fill').width(percentVal);
+    $('.upload-modal .progress-fill').html(percentVal);
+}
+
+function showUploadFeedback(event, position, total, percentComplete) {
+    var percentVal = percentComplete + '%';
+    $('.upload-modal .progress-fill').width(percentVal);
+    $('.upload-modal .progress-fill').html(percentVal);
+}
+
+function displayFinishedUpload(xhr) {
+    if (xhr.status == 200) {
+        markAsLoaded();
+    }
+
+    var resp = JSON.parse(xhr.responseText);
+    $('.upload-modal .embeddable-xml-input').val(xhr.getResponseHeader('asset_url'));
+    $('.upload-modal .embeddable').show();
+    $('.upload-modal .file-name').hide();
+    $('.upload-modal .progress-fill').html(resp.msg);
+    $('.upload-modal .choose-file-button').html(gettext('Load Another File')).show();
+    $('.upload-modal .progress-fill').width('100%');
+
+    // see if this id already exists, if so, then user must have updated an existing piece of content
+    $("tr[data-id='" + resp.url + "']").remove();
+
+    var template = $('#new-asset-element').html();
+    var html = Mustache.to_html(template, resp);
+    $('table > tbody').prepend(html);
+
+    // re-bind the listeners to delete it
+    $('.remove-asset-button').bind('click', removeAsset);
+
+    analytics.track('Uploaded a File', {
+        'course': course_location_analytics,
+        'asset_url': resp.url
+    });
+}
\ No newline at end of file
diff --git a/cms/static/sass/views/_assets.scss b/cms/static/sass/views/_assets.scss
index d01dd988ef..d4cff42ee9 100644
--- a/cms/static/sass/views/_assets.scss
+++ b/cms/static/sass/views/_assets.scss
@@ -76,6 +76,10 @@ body.course.uploads {
         width: 250px;
       }
 
+      .delete-col {
+        width: 20px;
+      }
+
       .embeddable-xml-input {
         @include box-shadow(none);
         width: 100%;
diff --git a/cms/templates/asset_index.html b/cms/templates/asset_index.html
index f03a9012f8..e8dc523ba7 100644
--- a/cms/templates/asset_index.html
+++ b/cms/templates/asset_index.html
@@ -1,5 +1,6 @@
 <%inherit file="base.html" />
 <%! from django.core.urlresolvers import reverse %>
+<%! from django.utils.translation import ugettext as _ %>
 <%block name="bodyclass">is-signedin course uploads</%block>
 <%block name="title">Files &amp; Uploads</%block>
 
@@ -7,6 +8,12 @@
 
 <%block name="jsextra">
 <script src="${static.url('js/vendor/mustache.js')}"></script>
+<script type="text/javascript" src="${static.url('js/views/assets.js')}"></script>
+
+<script type='text/javascript'>
+  // we just want a singleton
+  confirm_delete_prompt = null;
+</script>
 </%block>
 
 <%block name="content">
@@ -30,6 +37,9 @@
       <td class="embed-col">
         <input type="text" class="embeddable-xml-input" value='{{url}}' readonly>
       </td>
+      <td class="delete-col">
+        <a href="#" data-tooltip="${_('Delete this asset')}" class="remove-asset-button"><span class="delete-icon"></span></a>
+      </td>
     </tr>
   </script>
 
@@ -56,7 +66,7 @@
       <div class="page-actions">
         <input type="text" class="asset-search-input search wip-box" placeholder="search assets" style="display:none"/>
       </div>
-      <article class="asset-library">
+      <article class="asset-library" data-remove-asset-callback-url='${remove_asset_callback_url}'>
         <table>
           <thead>
             <tr>
@@ -64,6 +74,7 @@
               <th class="name-col">Name</th>
               <th class="date-col">Date Added</th>
               <th class="embed-col">URL</th>
+              <th class="delete-col"></th>
             </tr>
           </thead>
           <tbody id="asset_table_body">
@@ -86,6 +97,9 @@
               <td class="embed-col">
                 <input type="text" class="embeddable-xml-input" value="${asset['url']}" readonly>
               </td>
+              <td class="delete-col">
+                <a href="#" data-tooltip="${_('Delete this asset')}" class="remove-asset-button"><span class="delete-icon"></span></a>
+              </td>             
             </tr>
           % endfor
           </tbody>
@@ -129,3 +143,21 @@
 
 
 </%block>
+
+<%block name="view_alerts">
+<!-- alert: save confirmed with close -->
+<div class="wrapper wrapper-alert wrapper-alert-confirmation" role="status">
+  <div class="alert confirmation">
+    <i class="icon-ok"></i>
+
+    <div class="copy">
+      <h2 class="title title-3">${_('Your file has been deleted.')}</h2>
+    </div>
+
+    <a href="" rel="view" class="action action-alert-close">
+      <i class="icon-remove-sign"></i>
+      <span class="label">${_('close alert')}</span>
+    </a>
+  </div>
+</div>
+</%block>
diff --git a/cms/urls.py b/cms/urls.py
index e7444de4e9..a9a7f0a68a 100644
--- a/cms/urls.py
+++ b/cms/urls.py
@@ -35,6 +35,8 @@ urlpatterns = ('',  # nopep8
         'contentstore.views.preview_dispatch', name='preview_dispatch'),
     url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)/upload_asset$',
         'contentstore.views.upload_asset', name='upload_asset'),
+
+
     url(r'^manage_users/(?P<location>.*?)$', 'contentstore.views.manage_users', name='manage_users'),
     url(r'^add_user/(?P<location>.*?)$',
         'contentstore.views.add_user', name='add_user'),
@@ -71,8 +73,11 @@ urlpatterns = ('',  # nopep8
         'contentstore.views.edit_static', name='edit_static'),
     url(r'^edit_tabs/(?P<org>[^/]+)/(?P<course>[^/]+)/course/(?P<coursename>[^/]+)$',
         'contentstore.views.edit_tabs', name='edit_tabs'),
+
     url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)$',
         'contentstore.views.asset_index', name='asset_index'),
+    url(r'^(?P<org>[^/]+)/(?P<course>[^/]+)/assets/(?P<name>[^/]+)/remove$',
+        'contentstore.views.assets.remove_asset', name='remove_asset'),
 
     # this is a generic method to return the data/metadata associated with a xmodule
     url(r'^module_info/(?P<module_location>.*)$',
diff --git a/common/djangoapps/terrain/ui_helpers.py b/common/djangoapps/terrain/ui_helpers.py
index ecd43eb719..b1c5f30467 100644
--- a/common/djangoapps/terrain/ui_helpers.py
+++ b/common/djangoapps/terrain/ui_helpers.py
@@ -3,6 +3,7 @@
 
 from lettuce import world
 import time
+import platform
 from urllib import quote_plus
 from selenium.common.exceptions import WebDriverException, StaleElementReferenceException
 from selenium.webdriver.support import expected_conditions as EC
@@ -57,20 +58,28 @@ def css_find(css, wait_time=5):
 
 
 @world.absorb
-def css_click(css_selector):
+def css_click(css_selector, index=0, attempts=5):
     """
     Perform a click on a CSS selector, retrying if it initially fails
+    This function will return if the click worked (since it is try/excepting all errors)
     """
     assert is_css_present(css_selector)
-    try:
-        world.browser.find_by_css(css_selector).click()
-
-    except WebDriverException:
-        # Occassionally, MathJax or other JavaScript can cover up
-        # an element  temporarily.
-        # If this happens, wait a second, then try again
-        world.wait(1)
-        world.browser.find_by_css(css_selector).click()
+    attempt = 0
+    result = False
+    while attempt < attempts:
+        try:
+            world.css_find(css_selector)[index].click()
+            result = True
+            break
+        except WebDriverException:
+            # Occasionally, MathJax or other JavaScript can cover up
+            # an element temporarily.
+            # If this happens, wait a second, then try again
+            world.wait(1)
+            attempt += 1
+        except:
+            attempt += 1
+    return result
 
 
 @world.absorb
@@ -158,3 +167,8 @@ def click_tools():
     tools_css = 'li.nav-course-tools'
     if world.browser.is_element_present_by_css(tools_css):
         world.css_click(tools_css)
+
+
+@world.absorb
+def is_mac():
+    return platform.mac_ver()[0] is not ''
diff --git a/common/lib/xmodule/xmodule/capa_module.py b/common/lib/xmodule/xmodule/capa_module.py
index ca10d4d2a0..fee80a34ff 100644
--- a/common/lib/xmodule/xmodule/capa_module.py
+++ b/common/lib/xmodule/xmodule/capa_module.py
@@ -117,6 +117,8 @@ class CapaModule(CapaFields, XModule):
     '''
     An XModule implementing LonCapa format problems, implemented by way of
     capa.capa_problem.LoncapaProblem
+
+    CapaModule.__init__ takes the same arguments as xmodule.x_module:XModule.__init__
     '''
     icon_class = 'problem'
 
@@ -131,8 +133,9 @@ class CapaModule(CapaFields, XModule):
     js_module_name = "Problem"
     css = {'scss': [resource_string(__name__, 'css/capa/display.scss')]}
 
-    def __init__(self, system, location, descriptor, model_data):
-        XModule.__init__(self, system, location, descriptor, model_data)
+    def __init__(self, *args, **kwargs):
+        """ Accepts the same arguments as xmodule.x_module:XModule.__init__ """
+        XModule.__init__(self, *args, **kwargs)
 
         due_date = self.due
 
diff --git a/common/lib/xmodule/xmodule/combined_open_ended_module.py b/common/lib/xmodule/xmodule/combined_open_ended_module.py
index dc753a64b8..ac95567946 100644
--- a/common/lib/xmodule/xmodule/combined_open_ended_module.py
+++ b/common/lib/xmodule/xmodule/combined_open_ended_module.py
@@ -116,6 +116,8 @@ class CombinedOpenEndedModule(CombinedOpenEndedFields, XModule):
     incorporates multiple children (tasks):
         openendedmodule
         selfassessmentmodule
+
+    CombinedOpenEndedModule.__init__ takes the same arguments as xmodule.x_module:XModule.__init__
     """
     STATE_VERSION = 1
 
@@ -139,8 +141,7 @@ class CombinedOpenEndedModule(CombinedOpenEndedFields, XModule):
 
     css = {'scss': [resource_string(__name__, 'css/combinedopenended/display.scss')]}
 
-    def __init__(self, system, location, descriptor, model_data):
-        XModule.__init__(self, system, location, descriptor, model_data)
+    def __init__(self, *args, **kwargs):
         """
         Definition file should have one or many task blocks, a rubric block, and a prompt block:
 
@@ -175,9 +176,9 @@ class CombinedOpenEndedModule(CombinedOpenEndedFields, XModule):
         </combinedopenended>
 
         """
+        XModule.__init__(self, *args, **kwargs)
 
-        self.system = system
-        self.system.set('location', location)
+        self.system.set('location', self.location)
 
         if self.task_states is None:
             self.task_states = []
@@ -189,13 +190,11 @@ class CombinedOpenEndedModule(CombinedOpenEndedFields, XModule):
 
         attributes = self.student_attributes + self.settings_attributes
 
-        static_data = {
-            'rewrite_content_links': self.rewrite_content_links,
-        }
+        static_data = {}
         instance_state = {k: getattr(self, k) for k in attributes}
         self.child_descriptor = version_tuple.descriptor(self.system)
         self.child_definition = version_tuple.descriptor.definition_from_xml(etree.fromstring(self.data), self.system)
-        self.child_module = version_tuple.module(self.system, location, self.child_definition, self.child_descriptor,
+        self.child_module = version_tuple.module(self.system, self.location, self.child_definition, self.child_descriptor,
                                                  instance_state=instance_state, static_data=static_data,
                                                  attributes=attributes)
         self.save_instance_data()
diff --git a/common/lib/xmodule/xmodule/contentstore/django.py b/common/lib/xmodule/xmodule/contentstore/django.py
index 83a2508d96..f163348cc8 100644
--- a/common/lib/xmodule/xmodule/contentstore/django.py
+++ b/common/lib/xmodule/xmodule/contentstore/django.py
@@ -3,7 +3,7 @@ from importlib import import_module
 
 from django.conf import settings
 
-_CONTENTSTORE = None
+_CONTENTSTORE = {}
 
 
 def load_function(path):
@@ -17,13 +17,16 @@ def load_function(path):
     return getattr(import_module(module_path), name)
 
 
-def contentstore():
+def contentstore(name='default'):
     global _CONTENTSTORE
 
-    if _CONTENTSTORE is None:
+    if name not in _CONTENTSTORE:
         class_ = load_function(settings.CONTENTSTORE['ENGINE'])
         options = {}
         options.update(settings.CONTENTSTORE['OPTIONS'])
-        _CONTENTSTORE = class_(**options)
+        if 'ADDITIONAL_OPTIONS' in settings.CONTENTSTORE:
+            if name in settings.CONTENTSTORE['ADDITIONAL_OPTIONS']:
+                options.update(settings.CONTENTSTORE['ADDITIONAL_OPTIONS'][name])
+        _CONTENTSTORE[name] = class_(**options)
 
-    return _CONTENTSTORE
+    return _CONTENTSTORE[name]
diff --git a/common/lib/xmodule/xmodule/contentstore/mongo.py b/common/lib/xmodule/xmodule/contentstore/mongo.py
index 58fadb7957..fa0fc95181 100644
--- a/common/lib/xmodule/xmodule/contentstore/mongo.py
+++ b/common/lib/xmodule/xmodule/contentstore/mongo.py
@@ -1,4 +1,3 @@
-from bson.son import SON
 from pymongo import Connection
 import gridfs
 from gridfs.errors import NoFile
@@ -15,15 +14,16 @@ import os
 
 
 class MongoContentStore(ContentStore):
-    def __init__(self, host, db, port=27017, user=None, password=None, **kwargs):
+    def __init__(self, host, db, port=27017, user=None, password=None, bucket='fs', **kwargs):
         logging.debug('Using MongoDB for static content serving at host={0} db={1}'.format(host, db))
         _db = Connection(host=host, port=port, **kwargs)[db]
 
         if user is not None and password is not None:
             _db.authenticate(user, password)
 
-        self.fs = gridfs.GridFS(_db)
-        self.fs_files = _db["fs.files"]   # the underlying collection GridFS uses
+        self.fs = gridfs.GridFS(_db, bucket)
+
+        self.fs_files = _db[bucket + ".files"]   # the underlying collection GridFS uses
 
     def save(self, content):
         id = content.get_id()
@@ -43,7 +43,7 @@ class MongoContentStore(ContentStore):
         if self.fs.exists({"_id": id}):
             self.fs.delete(id)
 
-    def find(self, location):
+    def find(self, location, throw_on_not_found=True):
         id = StaticContent.get_id_from_location(location)
         try:
             with self.fs.get(id) as fp:
@@ -52,7 +52,10 @@ class MongoContentStore(ContentStore):
                                      thumbnail_location=fp.thumbnail_location if hasattr(fp, 'thumbnail_location') else None,
                                      import_path=fp.import_path if hasattr(fp, 'import_path') else None)
         except NoFile:
-            raise NotFoundError()
+            if throw_on_not_found:
+                raise NotFoundError()
+            else:
+                return None
 
     def export(self, location, output_directory):
         content = self.find(location)
diff --git a/common/lib/xmodule/xmodule/contentstore/utils.py b/common/lib/xmodule/xmodule/contentstore/utils.py
new file mode 100644
index 0000000000..74c4242bd9
--- /dev/null
+++ b/common/lib/xmodule/xmodule/contentstore/utils.py
@@ -0,0 +1,49 @@
+from xmodule.modulestore import Location
+from xmodule.contentstore.content import StaticContent
+from .django import contentstore
+
+
+def empty_asset_trashcan(course_locs):
+    '''
+    This method will hard delete all assets (optionally within a course_id) from the trashcan
+    '''
+    store = contentstore('trashcan')
+
+    for course_loc in course_locs:
+        # first delete all of the thumbnails
+        thumbs = store.get_all_content_thumbnails_for_course(course_loc)
+        for thumb in thumbs:
+            thumb_loc = Location(thumb["_id"])
+            id = StaticContent.get_id_from_location(thumb_loc)
+            print "Deleting {0}...".format(id)
+            store.delete(id)
+
+        # then delete all of the assets
+        assets = store.get_all_content_for_course(course_loc)
+        for asset in assets:
+            asset_loc = Location(asset["_id"])
+            id = StaticContent.get_id_from_location(asset_loc)
+            print "Deleting {0}...".format(id)
+            store.delete(id)
+
+
+def restore_asset_from_trashcan(location):
+    '''
+    This method will restore an asset which got soft deleted and put back in the original course
+    '''
+    trash = contentstore('trashcan')
+    store = contentstore()
+
+    loc = StaticContent.get_location_from_path(location)
+    content = trash.find(loc)
+
+    # ok, save the content into the courseware
+    store.save(content)
+
+    # see if there is a thumbnail as well, if so move that as well
+    if content.thumbnail_location is not None:
+        try:
+            thumbnail_content = trash.find(content.thumbnail_location)
+            store.save(thumbnail_content)
+        except:
+            pass  # OK if this is left dangling
diff --git a/common/lib/xmodule/xmodule/error_module.py b/common/lib/xmodule/xmodule/error_module.py
index e998ceb58e..a37081c447 100644
--- a/common/lib/xmodule/xmodule/error_module.py
+++ b/common/lib/xmodule/xmodule/error_module.py
@@ -94,11 +94,11 @@ class ErrorDescriptor(ErrorFields, JSONEditingDescriptor):
         model_data = {
             'error_msg': str(error_msg),
             'contents': contents,
-            'display_name': 'Error: ' + location.name
+            'display_name': 'Error: ' + location.name,
+            'location': location,
         }
         return cls(
             system,
-            location,
             model_data,
         )
 
diff --git a/common/lib/xmodule/xmodule/js/src/videoalpha/display/video_player.coffee b/common/lib/xmodule/xmodule/js/src/videoalpha/display/video_player.coffee
index 6e08589187..31dd115fa6 100644
--- a/common/lib/xmodule/xmodule/js/src/videoalpha/display/video_player.coffee
+++ b/common/lib/xmodule/xmodule/js/src/videoalpha/display/video_player.coffee
@@ -74,6 +74,9 @@ class @VideoPlayerAlpha extends SubviewAlpha
     # when this change is requested (instead of simply requesting a speed change to 1.0). This has to
     # be done only when the video is being watched in Firefox. We need to figure out what browser is
     # currently executing this code.
+    #
+    # TODO: Check the status of http://code.google.com/p/gdata-issues/issues/detail?id=4654
+    #       When the YouTube team fixes the API bug, we can remove this temporary bug fix.
     @video.isFirefox = navigator.userAgent.toLowerCase().indexOf('firefox') > -1
 
     if @video.videoType is 'html5'
@@ -252,6 +255,9 @@ class @VideoPlayerAlpha extends SubviewAlpha
     # or when we are in Firefox, and the new speed is 1.0. The second case is necessary to
     # avoid the bug where in Firefox speed switching to 1.0 in HTML5 player mode is handled
     # incorrectly by YouTube API.
+    #
+    # TODO: Check the status of http://code.google.com/p/gdata-issues/issues/detail?id=4654
+    #       When the YouTube team fixes the API bug, we can remove this temporary bug fix.
     if (@video.videoType is 'youtube') or ((@video.isFirefox) and (@video.playerType is 'youtube') and (newSpeed is '1.0'))
       if @isPlaying()
         @player.loadVideoById(@video.youtubeId(), @currentTime)
diff --git a/common/lib/xmodule/xmodule/mako_module.py b/common/lib/xmodule/xmodule/mako_module.py
index 8abb1d7777..526fc1a0eb 100644
--- a/common/lib/xmodule/xmodule/mako_module.py
+++ b/common/lib/xmodule/xmodule/mako_module.py
@@ -18,14 +18,16 @@ class MakoModuleDescriptor(XModuleDescriptor):
     Expects the descriptor to have the `mako_template` attribute set
     with the name of the template to render, and it will pass
     the descriptor as the `module` parameter to that template
+
+    MakoModuleDescriptor.__init__ takes the same arguments as xmodule.x_module:XModuleDescriptor.__init__
     """
 
-    def __init__(self, system, location, model_data):
-        if getattr(system, 'render_template', None) is None:
-            raise TypeError('{system} must have a render_template function'
+    def __init__(self, *args, **kwargs):
+        super(MakoModuleDescriptor, self).__init__(*args, **kwargs)
+        if getattr(self.runtime, 'render_template', None) is None:
+            raise TypeError('{runtime} must have a render_template function'
                             ' in order to use a MakoDescriptor'.format(
-                    system=system))
-        super(MakoModuleDescriptor, self).__init__(system, location, model_data)
+                    runtime=self.runtime))
 
     def get_context(self):
         """
diff --git a/common/lib/xmodule/xmodule/modulestore/mongo.py b/common/lib/xmodule/xmodule/modulestore/mongo.py
index 87a995cd06..422abbdd73 100644
--- a/common/lib/xmodule/xmodule/modulestore/mongo.py
+++ b/common/lib/xmodule/xmodule/modulestore/mongo.py
@@ -37,15 +37,23 @@ def get_course_id_no_run(location):
     return "/".join([location.org, location.course])
 
 
+class InvalidWriteError(Exception):
+    """
+    Raised to indicate that writing to a particular key
+    in the KeyValueStore is disabled
+    """
+
+
 class MongoKeyValueStore(KeyValueStore):
     """
     A KeyValueStore that maps keyed data access to one of the 3 data areas
     known to the MongoModuleStore (data, children, and metadata)
     """
-    def __init__(self, data, children, metadata):
+    def __init__(self, data, children, metadata, location):
         self._data = data
         self._children = children
         self._metadata = metadata
+        self._location = location
 
     def get(self, key):
         if key.scope == Scope.children:
@@ -55,7 +63,9 @@ class MongoKeyValueStore(KeyValueStore):
         elif key.scope == Scope.settings:
             return self._metadata[key.field_name]
         elif key.scope == Scope.content:
-            if key.field_name == 'data' and not isinstance(self._data, dict):
+            if key.field_name == 'location':
+                return self._location
+            elif key.field_name == 'data' and not isinstance(self._data, dict):
                 return self._data
             else:
                 return self._data[key.field_name]
@@ -68,7 +78,9 @@ class MongoKeyValueStore(KeyValueStore):
         elif key.scope == Scope.settings:
             self._metadata[key.field_name] = value
         elif key.scope == Scope.content:
-            if key.field_name == 'data' and not isinstance(self._data, dict):
+            if key.field_name == 'location':
+                self._location = value
+            elif key.field_name == 'data' and not isinstance(self._data, dict):
                 self._data = value
             else:
                 self._data[key.field_name] = value
@@ -82,7 +94,9 @@ class MongoKeyValueStore(KeyValueStore):
             if key.field_name in self._metadata:
                 del self._metadata[key.field_name]
         elif key.scope == Scope.content:
-            if key.field_name == 'data' and not isinstance(self._data, dict):
+            if key.field_name == 'location':
+                self._location = Location(None)
+            elif key.field_name == 'data' and not isinstance(self._data, dict):
                 self._data = None
             else:
                 del self._data[key.field_name]
@@ -95,7 +109,9 @@ class MongoKeyValueStore(KeyValueStore):
         elif key.scope == Scope.settings:
             return key.field_name in self._metadata
         elif key.scope == Scope.content:
-            if key.field_name == 'data' and not isinstance(self._data, dict):
+            if key.field_name == 'location':
+                return True
+            elif key.field_name == 'data' and not isinstance(self._data, dict):
                 return True
             else:
                 return key.field_name in self._data
@@ -171,10 +187,11 @@ class CachingDescriptorSystem(MakoDescriptorSystem):
                     definition.get('data', {}),
                     definition.get('children', []),
                     metadata,
+                    location,
                 )
 
                 model_data = DbModel(kvs, class_, None, MongoUsage(self.course_id, location))
-                module = class_(self, location, model_data)
+                module = class_(self, model_data)
                 if self.cached_metadata is not None:
                     # parent container pointers don't differentiate between draft and non-draft
                     # so when we do the lookup, we should do so with a non-draft location
diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py b/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
index 8a479fbf9e..07e6124537 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
@@ -1,11 +1,14 @@
 import pymongo
 
 from mock import Mock
-from nose.tools import assert_equals, assert_raises, assert_not_equals, with_setup, assert_false
+from nose.tools import assert_equals, assert_raises, assert_not_equals, assert_false
 from pprint import pprint
 
+from xblock.core import Scope
+from xblock.runtime import KeyValueStore, InvalidScopeError
+
 from xmodule.modulestore import Location
-from xmodule.modulestore.mongo import MongoModuleStore
+from xmodule.modulestore.mongo import MongoModuleStore, MongoKeyValueStore
 from xmodule.modulestore.xml_importer import import_from_xml
 from xmodule.templates import update_templates
 
@@ -114,3 +117,75 @@ class TestMongoModuleStore(object):
                 course.location.org == 'edx' and course.location.course == 'templates',
                 '{0} is a template course'.format(course)
             )
+
+class TestMongoKeyValueStore(object):
+
+    def setUp(self):
+        self.data = {'foo': 'foo_value'}
+        self.location = Location('i4x://org/course/category/name@version')
+        self.children = ['i4x://org/course/child/a', 'i4x://org/course/child/b']
+        self.metadata = {'meta': 'meta_val'}
+        self.kvs = MongoKeyValueStore(self.data, self.children, self.metadata, self.location)
+
+    def _check_read(self, key, expected_value):
+        assert_equals(expected_value, self.kvs.get(key))
+        assert self.kvs.has(key)
+
+    def test_read(self):
+        assert_equals(self.data['foo'], self.kvs.get(KeyValueStore.Key(Scope.content, None, None, 'foo')))
+        assert_equals(self.location, self.kvs.get(KeyValueStore.Key(Scope.content, None, None, 'location')))
+        assert_equals(self.children, self.kvs.get(KeyValueStore.Key(Scope.children, None, None, 'children')))
+        assert_equals(self.metadata['meta'], self.kvs.get(KeyValueStore.Key(Scope.settings, None, None, 'meta')))
+        assert_equals(None, self.kvs.get(KeyValueStore.Key(Scope.parent, None, None, 'parent')))
+
+    def test_read_invalid_scope(self):
+        for scope in (Scope.preferences, Scope.user_info, Scope.user_state):
+            key = KeyValueStore.Key(scope, None, None, 'foo')
+            with assert_raises(InvalidScopeError):
+                self.kvs.get(key)
+            assert_false(self.kvs.has(key))
+
+    def test_read_non_dict_data(self):
+        self.kvs._data = 'xml_data'
+        assert_equals('xml_data', self.kvs.get(KeyValueStore.Key(Scope.content, None, None, 'data')))
+
+    def _check_write(self, key, value):
+        self.kvs.set(key, value)
+        assert_equals(value, self.kvs.get(key))
+
+    def test_write(self):
+        yield (self._check_write, KeyValueStore.Key(Scope.content, None, None, 'foo'), 'new_data')
+        yield (self._check_write, KeyValueStore.Key(Scope.content, None, None, 'location'), Location('i4x://org/course/category/name@new_version'))
+        yield (self._check_write, KeyValueStore.Key(Scope.children, None, None, 'children'), [])
+        yield (self._check_write, KeyValueStore.Key(Scope.settings, None, None, 'meta'), 'new_settings')
+
+    def test_write_non_dict_data(self):
+        self.kvs._data = 'xml_data'
+        self._check_write(KeyValueStore.Key(Scope.content, None, None, 'data'), 'new_data')
+
+    def test_write_invalid_scope(self):
+        for scope in (Scope.preferences, Scope.user_info, Scope.user_state, Scope.parent):
+            with assert_raises(InvalidScopeError):
+                self.kvs.set(KeyValueStore.Key(scope, None, None, 'foo'), 'new_value')
+
+    def _check_delete_default(self, key, default_value):
+        self.kvs.delete(key)
+        assert_equals(default_value, self.kvs.get(key))
+        assert self.kvs.has(key)
+
+    def _check_delete_key_error(self, key):
+        self.kvs.delete(key)
+        with assert_raises(KeyError):
+            self.kvs.get(key)
+        assert_false(self.kvs.has(key))
+
+    def test_delete(self):
+        yield (self._check_delete_key_error, KeyValueStore.Key(Scope.content, None, None, 'foo'))
+        yield (self._check_delete_default, KeyValueStore.Key(Scope.content, None, None, 'location'), Location(None))
+        yield (self._check_delete_default, KeyValueStore.Key(Scope.children, None, None, 'children'), [])
+        yield (self._check_delete_key_error, KeyValueStore.Key(Scope.settings, None, None, 'meta'))
+
+    def test_delete_invalid_scope(self):
+        for scope in (Scope.preferences, Scope.user_info, Scope.user_state, Scope.parent):
+            with assert_raises(InvalidScopeError):
+                self.kvs.delete(KeyValueStore.Key(scope, None, None, 'foo'))
diff --git a/common/lib/xmodule/xmodule/modulestore/xml.py b/common/lib/xmodule/xmodule/modulestore/xml.py
index 6ab6843216..a704fc2ae8 100644
--- a/common/lib/xmodule/xmodule/modulestore/xml.py
+++ b/common/lib/xmodule/xmodule/modulestore/xml.py
@@ -463,7 +463,7 @@ class XMLModuleStore(ModuleStoreBase):
                     # tabs are referenced in policy.json through a 'slug' which is just the filename without the .html suffix
                     slug = os.path.splitext(os.path.basename(filepath))[0]
                     loc = Location('i4x', course_descriptor.location.org, course_descriptor.location.course, category, slug)
-                    module = HtmlDescriptor(system, loc, {'data': html})
+                    module = HtmlDescriptor(system, {'data': html, 'location': loc})
                     # VS[compat]:
                     # Hack because we need to pull in the 'display_name' for static tabs (because we need to edit them)
                     # from the course policy
diff --git a/common/lib/xmodule/xmodule/open_ended_grading_classes/combined_open_ended_modulev1.py b/common/lib/xmodule/xmodule/open_ended_grading_classes/combined_open_ended_modulev1.py
index b48c70c8d5..45e73442d0 100644
--- a/common/lib/xmodule/xmodule/open_ended_grading_classes/combined_open_ended_modulev1.py
+++ b/common/lib/xmodule/xmodule/open_ended_grading_classes/combined_open_ended_modulev1.py
@@ -117,7 +117,6 @@ class CombinedOpenEndedV1Module():
 
         self.instance_state = instance_state
         self.display_name = instance_state.get('display_name', "Open Ended")
-        self.rewrite_content_links = static_data.get('rewrite_content_links', "")
 
         #We need to set the location here so the child modules can use it
         system.set('location', location)
@@ -354,17 +353,7 @@ class CombinedOpenEndedV1Module():
         Output: Child task HTML
         """
         self.update_task_states()
-        html = self.current_task.get_html(self.system)
-        return_html = html
-        try:
-            #Without try except block, get this error:
-            # File "/home/vik/mitx_all/mitx/common/lib/xmodule/xmodule/x_module.py", line 263, in rewrite_content_links
-            # if link.startswith(XASSET_SRCREF_PREFIX):
-            # Placing try except so that if the error is fixed, this code will start working again.
-            return_html = rewrite_links(html, self.rewrite_content_links)
-        except Exception:
-            pass
-        return return_html
+        return self.current_task.get_html(self.system)
 
     def get_current_attributes(self, task_number):
         """
diff --git a/common/lib/xmodule/xmodule/peer_grading_module.py b/common/lib/xmodule/xmodule/peer_grading_module.py
index 979bc95cb0..a13fef8e40 100644
--- a/common/lib/xmodule/xmodule/peer_grading_module.py
+++ b/common/lib/xmodule/xmodule/peer_grading_module.py
@@ -62,6 +62,9 @@ class PeerGradingFields(object):
 
 
 class PeerGradingModule(PeerGradingFields, XModule):
+    """
+    PeerGradingModule.__init__ takes the same arguments as xmodule.x_module:XModule.__init__
+    """
     _VERSION = 1
 
     js = {'coffee': [resource_string(__name__, 'js/src/peergrading/peer_grading.coffee'),
@@ -73,12 +76,11 @@ class PeerGradingModule(PeerGradingFields, XModule):
 
     css = {'scss': [resource_string(__name__, 'css/combinedopenended/display.scss')]}
 
-    def __init__(self, system, location, descriptor, model_data):
-        XModule.__init__(self, system, location, descriptor, model_data)
+    def __init__(self, *args, **kwargs):
+        super(PeerGradingModule, self).__init__(*args, **kwargs)
 
-        # We need to set the location here so the child modules can use it
-        system.set('location', location)
-        self.system = system
+        #We need to set the location here so the child modules can use it
+        self.runtime.set('location', self.location)
         if (self.system.open_ended_grading_interface):
             self.peer_gs = PeerGradingService(self.system.open_ended_grading_interface, self.system)
         else:
diff --git a/common/lib/xmodule/xmodule/tests/test_annotatable_module.py b/common/lib/xmodule/xmodule/tests/test_annotatable_module.py
index 43eae8e43e..268f743421 100644
--- a/common/lib/xmodule/xmodule/tests/test_annotatable_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_annotatable_module.py
@@ -29,10 +29,10 @@ class AnnotatableModuleTestCase(unittest.TestCase):
         </annotatable>
     '''
     descriptor = Mock()
-    module_data = {'data': sample_xml}
+    module_data = {'data': sample_xml, 'location': location}
 
     def setUp(self):
-        self.annotatable = AnnotatableModule(test_system(), self.location, self.descriptor, self.module_data)
+        self.annotatable = AnnotatableModule(test_system(), self.descriptor, self.module_data)
 
     def test_annotation_data_attr(self):
         el = etree.fromstring('<annotation title="bar" body="foo" problem="0">test</annotation>')
diff --git a/common/lib/xmodule/xmodule/tests/test_capa_module.py b/common/lib/xmodule/xmodule/tests/test_capa_module.py
index 3153250527..7cba4a76b3 100644
--- a/common/lib/xmodule/xmodule/tests/test_capa_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_capa_module.py
@@ -86,7 +86,7 @@ class CapaFactory(object):
         """
         location = Location(["i4x", "edX", "capa_test", "problem",
                              "SampleProblem{0}".format(CapaFactory.next_num())])
-        model_data = {'data': CapaFactory.sample_problem_xml}
+        model_data = {'data': CapaFactory.sample_problem_xml, 'location': location}
 
         if graceperiod is not None:
             model_data['graceperiod'] = graceperiod
@@ -113,7 +113,7 @@ class CapaFactory(object):
 
         system = test_system()
         system.render_template = Mock(return_value="<div>Test Template HTML</div>")
-        module = CapaModule(system, location, descriptor, model_data)
+        module = CapaModule(system, descriptor, model_data)
 
         if correct:
             # TODO: probably better to actually set the internal state properly, but...
diff --git a/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py b/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
index 409347882f..7dbaf6fe3d 100644
--- a/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
+++ b/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
@@ -175,7 +175,6 @@ class OpenEndedModuleTest(unittest.TestCase):
         'max_score': max_score,
         'display_name': 'Name',
         'accept_file_upload': False,
-        'rewrite_content_links': "",
         'close_date': None,
         's3_interface': test_util_open_ended.S3_INTERFACE,
         'open_ended_grading_interface': test_util_open_ended.OPEN_ENDED_GRADING_INTERFACE,
@@ -332,7 +331,6 @@ class CombinedOpenEndedModuleTest(unittest.TestCase):
         'max_score': max_score,
         'display_name': 'Name',
         'accept_file_upload': False,
-        'rewrite_content_links': "",
         'close_date': "",
         's3_interface': test_util_open_ended.S3_INTERFACE,
         'open_ended_grading_interface': test_util_open_ended.OPEN_ENDED_GRADING_INTERFACE,
@@ -370,10 +368,15 @@ class CombinedOpenEndedModuleTest(unittest.TestCase):
     full_definition = definition_template.format(prompt=prompt, rubric=rubric, task1=task_xml1, task2=task_xml2)
     descriptor = Mock(data=full_definition)
     test_system = test_system()
-    combinedoe_container = CombinedOpenEndedModule(test_system,
-                                                   location,
-                                                   descriptor,
-                                                   model_data={'data': full_definition, 'weight': '1'})
+    combinedoe_container = CombinedOpenEndedModule(
+        test_system,
+        descriptor,
+        model_data={
+            'data': full_definition,
+            'weight': '1',
+            'location': location
+        }
+    )
 
     def setUp(self):
         # TODO: this constructor call is definitely wrong, but neither branch
diff --git a/common/lib/xmodule/xmodule/tests/test_conditional.py b/common/lib/xmodule/xmodule/tests/test_conditional.py
index 320b94efb7..e88bf0c588 100644
--- a/common/lib/xmodule/xmodule/tests/test_conditional.py
+++ b/common/lib/xmodule/xmodule/tests/test_conditional.py
@@ -60,9 +60,9 @@ class ConditionalFactory(object):
         source_location = Location(["i4x", "edX", "conditional_test", "problem", "SampleProblem"])
         if source_is_error_module:
             # Make an error descriptor and module
-            source_descriptor = NonStaffErrorDescriptor.from_xml('some random xml data', 
+            source_descriptor = NonStaffErrorDescriptor.from_xml('some random xml data',
                                                                  system,
-                                                                 org=source_location.org, 
+                                                                 org=source_location.org,
                                                                  course=source_location.course,
                                                                  error_msg='random error message')
             source_module = source_descriptor.xmodule(system)
@@ -87,8 +87,8 @@ class ConditionalFactory(object):
 
         # construct conditional module:
         cond_location = Location(["i4x", "edX", "conditional_test", "conditional", "SampleConditional"])
-        model_data = {'data': '<conditional/>'}
-        cond_module = ConditionalModule(system, cond_location, cond_descriptor, model_data)
+        model_data = {'data': '<conditional/>', 'location': cond_location}
+        cond_module = ConditionalModule(system, cond_descriptor, model_data)
 
         # return dict:
         return {'cond_module': cond_module,
@@ -106,7 +106,7 @@ class ConditionalModuleBasicTest(unittest.TestCase):
         self.test_system = test_system()
 
     def test_icon_class(self):
-        '''verify that get_icon_class works independent of condition satisfaction''' 
+        '''verify that get_icon_class works independent of condition satisfaction'''
         modules = ConditionalFactory.create(self.test_system)
         for attempted in ["false", "true"]:
             for icon_class in [ 'other', 'problem', 'video']:
@@ -186,7 +186,6 @@ class ConditionalModuleXmlTest(unittest.TestCase):
             if isinstance(descriptor, Location):
                 location = descriptor
                 descriptor = self.modulestore.get_instance(course.id, location, depth=None)
-            location = descriptor.location
             return descriptor.xmodule(self.test_system)
 
         # edx - HarvardX
diff --git a/common/lib/xmodule/xmodule/tests/test_html_module.py b/common/lib/xmodule/xmodule/tests/test_html_module.py
index e56e9babe7..ea6b358f3b 100644
--- a/common/lib/xmodule/xmodule/tests/test_html_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_html_module.py
@@ -8,14 +8,13 @@ from xmodule.modulestore import Location
 from . import test_system
 
 class HtmlModuleSubstitutionTestCase(unittest.TestCase):
-    location = Location(["i4x", "edX", "toy", "html", "simple_html"])
     descriptor = Mock()
 
     def test_substitution_works(self):
         sample_xml = '''%%USER_ID%%'''
         module_data = {'data': sample_xml}
         module_system = test_system()
-        module = HtmlModule(module_system, self.location, self.descriptor, module_data)
+        module = HtmlModule(module_system, self.descriptor, module_data)
         self.assertEqual(module.get_html(), str(module_system.anonymous_student_id))
 
 
@@ -26,7 +25,7 @@ class HtmlModuleSubstitutionTestCase(unittest.TestCase):
             </html>
         '''
         module_data = {'data': sample_xml}
-        module = HtmlModule(test_system(), self.location, self.descriptor, module_data)
+        module = HtmlModule(test_system(), self.descriptor, module_data)
         self.assertEqual(module.get_html(), sample_xml)
 
 
@@ -35,6 +34,6 @@ class HtmlModuleSubstitutionTestCase(unittest.TestCase):
         module_data = {'data': sample_xml}
         module_system = test_system()
         module_system.anonymous_student_id = None
-        module = HtmlModule(module_system, self.location, self.descriptor, module_data)
+        module = HtmlModule(module_system, self.descriptor, module_data)
         self.assertEqual(module.get_html(), sample_xml)
 
diff --git a/common/lib/xmodule/xmodule/tests/test_logic.py b/common/lib/xmodule/xmodule/tests/test_logic.py
index e60af63921..ff17f88dfc 100644
--- a/common/lib/xmodule/xmodule/tests/test_logic.py
+++ b/common/lib/xmodule/xmodule/tests/test_logic.py
@@ -30,13 +30,13 @@ class LogicTest(unittest.TestCase):
             pass
 
         self.system = None
-        self.location = None
         self.descriptor = EmptyClass()
 
         self.xmodule_class = self.descriptor_class.module_class
         self.xmodule = self.xmodule_class(
-            self.system, self.location,
-            self.descriptor, self.raw_model_data
+            self.system,
+            self.descriptor,
+            self.raw_model_data
         )
 
     def ajax_request(self, dispatch, get):
diff --git a/common/lib/xmodule/xmodule/tests/test_mako_module.py b/common/lib/xmodule/xmodule/tests/test_mako_module.py
new file mode 100644
index 0000000000..7ba023bda7
--- /dev/null
+++ b/common/lib/xmodule/xmodule/tests/test_mako_module.py
@@ -0,0 +1,22 @@
+""" Test mako_module.py """
+
+from unittest import TestCase
+from mock import Mock
+
+from xmodule.mako_module import MakoModuleDescriptor
+
+
+class MakoModuleTest(TestCase):
+    """ Test MakoModuleDescriptor """
+
+    def test_render_template_check(self):
+        mock_system = Mock()
+        mock_system.render_template = None
+
+        with self.assertRaises(TypeError):
+            MakoModuleDescriptor(mock_system, {})
+
+        del mock_system.render_template
+
+        with self.assertRaises(TypeError):
+            MakoModuleDescriptor(mock_system, {})
diff --git a/common/lib/xmodule/xmodule/tests/test_progress.py b/common/lib/xmodule/xmodule/tests/test_progress.py
index 4bb663ad85..97ec00b13e 100644
--- a/common/lib/xmodule/xmodule/tests/test_progress.py
+++ b/common/lib/xmodule/xmodule/tests/test_progress.py
@@ -134,6 +134,6 @@ class ModuleProgressTest(unittest.TestCase):
     '''
     def test_xmodule_default(self):
         '''Make sure default get_progress exists, returns None'''
-        xm = x_module.XModule(test_system(), 'a://b/c/d/e', None, {})
+        xm = x_module.XModule(test_system(), None, {'location': 'a://b/c/d/e'})
         p = xm.get_progress()
         self.assertEqual(p, None)
diff --git a/lms/djangoapps/courseware/tests/test_video_xml.py b/common/lib/xmodule/xmodule/tests/test_video_xml.py
similarity index 97%
rename from lms/djangoapps/courseware/tests/test_video_xml.py
rename to common/lib/xmodule/xmodule/tests/test_video_xml.py
index 169e5be2d9..0dcec78d08 100644
--- a/lms/djangoapps/courseware/tests/test_video_xml.py
+++ b/common/lib/xmodule/xmodule/tests/test_video_xml.py
@@ -47,13 +47,13 @@ class VideoFactory(object):
         """Method return Video Xmodule instance."""
         location = Location(["i4x", "edX", "video", "default",
                              "SampleProblem1"])
-        model_data = {'data': VideoFactory.sample_problem_xml_youtube}
+        model_data = {'data': VideoFactory.sample_problem_xml_youtube, 'location': location}
 
         descriptor = Mock(weight="1", url_name="SampleProblem1")
 
         system = test_system()
         system.render_template = lambda template, context: context
-        module = VideoModule(system, location, descriptor, model_data)
+        module = VideoModule(system, descriptor, model_data)
 
         return module
 
diff --git a/common/lib/xmodule/xmodule/tests/test_xml_module.py b/common/lib/xmodule/xmodule/tests/test_xml_module.py
index eb715b44bc..46410def8e 100644
--- a/common/lib/xmodule/xmodule/tests/test_xml_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_xml_module.py
@@ -142,7 +142,7 @@ class EditableMetadataFieldsTest(unittest.TestCase):
     def get_xml_editable_fields(self, model_data):
         system = test_system()
         system.render_template = Mock(return_value="<div>Test Template HTML</div>")
-        return XmlDescriptor(system=system, location=None, model_data=model_data).editable_metadata_fields
+        return XmlDescriptor(runtime=system, model_data=model_data).editable_metadata_fields
 
     def get_descriptor(self, model_data):
         class TestModuleDescriptor(TestFields, XmlDescriptor):
@@ -154,7 +154,7 @@ class EditableMetadataFieldsTest(unittest.TestCase):
 
         system = test_system()
         system.render_template = Mock(return_value="<div>Test Template HTML</div>")
-        return TestModuleDescriptor(system=system, location=None, model_data=model_data)
+        return TestModuleDescriptor(runtime=system, model_data=model_data)
 
     def assert_field_values(self, editable_fields, name, field, explicitly_set, inheritable, value, default_value,
                             type='Generic', options=[]):
diff --git a/common/lib/xmodule/xmodule/x_module.py b/common/lib/xmodule/xmodule/x_module.py
index a1813a795a..3edc22df43 100644
--- a/common/lib/xmodule/xmodule/x_module.py
+++ b/common/lib/xmodule/xmodule/x_module.py
@@ -10,7 +10,7 @@ from pkg_resources import resource_listdir, resource_string, resource_isdir
 from xmodule.modulestore import Location
 from xmodule.modulestore.exceptions import ItemNotFoundError
 
-from xblock.core import XBlock, Scope, String, Integer, Float
+from xblock.core import XBlock, Scope, String, Integer, Float, ModelType
 
 log = logging.getLogger(__name__)
 
@@ -19,6 +19,23 @@ def dummy_track(event_type, event):
     pass
 
 
+class LocationField(ModelType):
+    """
+    XBlock field for storing Location values
+    """
+    def from_json(self, value):
+        """
+        Parse the json value as a Location
+        """
+        return Location(value)
+
+    def to_json(self, value):
+        """
+        Store the Location as a url string in json
+        """
+        return value.url()
+
+
 class HTMLSnippet(object):
     """
     A base class defining an interface for an object that is able to present an
@@ -87,6 +104,16 @@ class XModuleFields(object):
         default=None
     )
 
+    # Please note that in order to be compatible with XBlocks more generally,
+    # the LMS and CMS shouldn't be using this field. It's only for internal
+    # consumption by the XModules themselves
+    location = LocationField(
+        display_name="Location",
+        help="This is the location id for the XModule.",
+        scope=Scope.content,
+        default=Location(None),
+    )
+
 
 class XModule(XModuleFields, HTMLSnippet, XBlock):
     ''' Implements a generic learning module.
@@ -106,24 +133,20 @@ class XModule(XModuleFields, HTMLSnippet, XBlock):
     icon_class = 'other'
 
 
-    def __init__(self, system, location, descriptor, model_data):
+    def __init__(self, runtime, descriptor, model_data):
         '''
         Construct a new xmodule
 
-        system: A ModuleSystem allowing access to external resources
-
-        location: Something Location-like that identifies this xmodule
+        runtime: An XBlock runtime allowing access to external resources
 
         descriptor: the XModuleDescriptor that this module is an instance of.
-            TODO (vshnayder): remove the definition parameter and location--they
-            can come from the descriptor.
 
         model_data: A dictionary-like object that maps field names to values
             for those fields.
         '''
+        super(XModule, self).__init__(runtime, model_data)
         self._model_data = model_data
-        self.system = system
-        self.location = Location(location)
+        self.system = runtime
         self.descriptor = descriptor
         self.url_name = self.location.name
         self.category = self.location.category
@@ -254,19 +277,6 @@ class XModule(XModuleFields, HTMLSnippet, XBlock):
             get is a dictionary-like object '''
         return ""
 
-    # cdodge: added to support dynamic substitutions of
-    # links for courseware assets (e.g. images). <link> is passed through from lxml.html parser
-    def rewrite_content_links(self, link):
-        # see if we start with our format, e.g. 'xasset:<filename>'
-        if link.startswith(XASSET_SRCREF_PREFIX):
-            # yes, then parse out the name
-            name = link[len(XASSET_SRCREF_PREFIX):]
-            loc = Location(self.location)
-            # resolve the reference to our internal 'filepath' which
-            link = StaticContent.compute_location_filename(loc.org, loc.course, name)
-
-        return link
-
 
 def policy_key(location):
     """
@@ -340,13 +350,12 @@ class XModuleDescriptor(XModuleFields, HTMLSnippet, ResourceTemplates, XBlock):
     template_dir_name = "default"
 
     # Class level variable
+
+    # True if this descriptor always requires recalculation of grades, for
+    # example if the score can change via an extrnal service, not just when the
+    # student interacts with the module on the page.  A specific example is
+    # FoldIt, which posts grade-changing updates through a separate API.
     always_recalculate_grades = False
-    """
-    Return whether this descriptor always requires recalculation of grades, for
-    example if the score can change via an extrnal service, not just when the
-    student interacts with the module on the page.  A specific example is
-    FoldIt, which posts grade-changing updates through a separate API.
-    """
 
     # VS[compat].  Backwards compatibility code that can go away after
     # importing 2012 courses.
@@ -357,10 +366,7 @@ class XModuleDescriptor(XModuleFields, HTMLSnippet, ResourceTemplates, XBlock):
     }
 
     # ============================= STRUCTURAL MANIPULATION ===================
-    def __init__(self,
-                 system,
-                 location,
-                 model_data):
+    def __init__(self, *args, **kwargs):
         """
         Construct a new XModuleDescriptor. The only required arguments are the
         system, used for interaction with external resources, and the
@@ -371,19 +377,17 @@ class XModuleDescriptor(XModuleFields, HTMLSnippet, ResourceTemplates, XBlock):
         This allows for maximal flexibility to add to the interface while
         preserving backwards compatibility.
 
-        system: A DescriptorSystem for interacting with external resources
-
-        location: Something Location-like that identifies this xmodule
+        runtime: A DescriptorSystem for interacting with external resources
 
         model_data: A dictionary-like object that maps field names to values
             for those fields.
+
+        XModuleDescriptor.__init__ takes the same arguments as xblock.core:XBlock.__init__
         """
-        self.system = system
-        self.location = Location(location)
+        super(XModuleDescriptor, self).__init__(*args, **kwargs)
+        self.system = self.runtime
         self.url_name = self.location.name
         self.category = self.location.category
-        self._model_data = model_data
-
         self._child_instances = None
 
     @property
@@ -441,7 +445,6 @@ class XModuleDescriptor(XModuleFields, HTMLSnippet, ResourceTemplates, XBlock):
         """
         return self.module_class(
             system,
-            self.location,
             self,
             system.xblock_model_data(self),
         )
@@ -510,7 +513,9 @@ class XModuleDescriptor(XModuleFields, HTMLSnippet, ResourceTemplates, XBlock):
             else:
                 model_data['data'] = definition['data']
 
-        return cls(system=system, location=json_data['location'], model_data=model_data)
+        model_data['location'] = json_data['location']
+
+        return cls(system, model_data)
 
     @classmethod
     def _translate(cls, key):
diff --git a/common/lib/xmodule/xmodule/xml_module.py b/common/lib/xmodule/xmodule/xml_module.py
index 9b5de9d7e7..e1a0e0cf08 100644
--- a/common/lib/xmodule/xmodule/xml_module.py
+++ b/common/lib/xmodule/xmodule/xml_module.py
@@ -254,7 +254,7 @@ class XmlDescriptor(XModuleDescriptor):
         definition, children = cls.definition_from_xml(definition_xml, system)
         if definition_metadata:
             definition['definition_metadata'] = definition_metadata
-        definition['filename'] = [ filepath, filename ]     
+        definition['filename'] = [ filepath, filename ]
 
         return definition, children
 
@@ -352,10 +352,10 @@ class XmlDescriptor(XModuleDescriptor):
         for key, value in metadata.items():
             if key not in set(f.name for f in cls.fields + cls.lms.fields):
                 model_data['xml_attributes'][key] = value
+        model_data['location'] = location
 
         return cls(
             system,
-            location,
             model_data,
         )
 
diff --git a/lms/CHANGELOG.md b/lms/CHANGELOG.md
deleted file mode 100644
index 0794d379b9..0000000000
--- a/lms/CHANGELOG.md
+++ /dev/null
@@ -1,18 +0,0 @@
-Instructions
-============
-For each pull request, add one or more lines to the bottom of the change list. When
-code is released to production, change the `Upcoming` entry to todays date, and add
-a new block at the bottom of the file.
-
-    Upcoming
-    --------
-
-Change log entries should be targeted at end users. A good place to start is the
-user story that instigated the pull request.
-
-Changes
-=======
-
-Upcoming
---------
-* Created changelog
\ No newline at end of file
diff --git a/lms/djangoapps/courseware/tests/__init__.py b/lms/djangoapps/courseware/tests/__init__.py
index dc61239c36..cc53bf735a 100644
--- a/lms/djangoapps/courseware/tests/__init__.py
+++ b/lms/djangoapps/courseware/tests/__init__.py
@@ -77,14 +77,15 @@ class BaseTestXmodule(ModuleStoreTestCase):
             data=self.DATA
         )
 
-        location = self.item_descriptor.location
         system = test_system()
         system.render_template = lambda template, context: context
+        model_data = {'location': self.item_descriptor.location}
+        model_data.update(self.MODEL_DATA)
 
         self.item_module = self.item_descriptor.module_class(
-            system, location, self.item_descriptor, self.MODEL_DATA
+            system, self.item_descriptor, model_data
         )
-        self.item_url = Location(location).url()
+        self.item_url = Location(self.item_module.location).url()
 
         # login all users for acces to Xmodule
         self.clients = {user.username: Client() for user in self.users}
diff --git a/lms/djangoapps/courseware/tests/test_video_mongo.py b/lms/djangoapps/courseware/tests/test_video_mongo.py
index c041ccc151..a0fdecc77a 100644
--- a/lms/djangoapps/courseware/tests/test_video_mongo.py
+++ b/lms/djangoapps/courseware/tests/test_video_mongo.py
@@ -15,8 +15,8 @@ class TestVideo(BaseTestXmodule):
             user.username: self.clients[user.username].post(
                 self.get_url('whatever'),
                 {},
-                HTTP_X_REQUESTED_WITH='XMLHttpRequest')
-            for user in self.users
+                HTTP_X_REQUESTED_WITH='XMLHttpRequest'
+            ) for user in self.users
         }
 
         self.assertEqual(
diff --git a/lms/djangoapps/open_ended_grading/tests.py b/lms/djangoapps/open_ended_grading/tests.py
index 13d780df12..3b6c992881 100644
--- a/lms/djangoapps/open_ended_grading/tests.py
+++ b/lms/djangoapps/open_ended_grading/tests.py
@@ -160,7 +160,7 @@ class TestPeerGradingService(LoginEnrollmentTestCase):
         self.course_id = "edX/toy/2012_Fall"
         self.toy = modulestore().get_course(self.course_id)
         location = "i4x://edX/toy/peergrading/init"
-        model_data = {'data': "<peergrading/>"}
+        model_data = {'data': "<peergrading/>", 'location': location}
         self.mock_service = peer_grading_service.MockPeerGradingService()
         self.system = ModuleSystem(
             ajax_url=location,
@@ -172,9 +172,9 @@ class TestPeerGradingService(LoginEnrollmentTestCase):
             s3_interface=test_util_open_ended.S3_INTERFACE,
             open_ended_grading_interface=test_util_open_ended.OPEN_ENDED_GRADING_INTERFACE
         )
-        self.descriptor = peer_grading_module.PeerGradingDescriptor(self.system, location, model_data)
-        model_data = {}
-        self.peer_module = peer_grading_module.PeerGradingModule(self.system, location, self.descriptor, model_data)
+        self.descriptor = peer_grading_module.PeerGradingDescriptor(self.system, model_data)
+        model_data = {'location': location}
+        self.peer_module = peer_grading_module.PeerGradingModule(self.system, self.descriptor, model_data)
         self.peer_module.peer_gs = self.mock_service
         self.logout()
 
diff --git a/lms/envs/aws.py b/lms/envs/aws.py
index 73f49a6209..c8c49c2b1e 100644
--- a/lms/envs/aws.py
+++ b/lms/envs/aws.py
@@ -172,18 +172,19 @@ for name, value in ENV_TOKENS.get("CODE_JAIL", {}).items():
 
 COURSES_WITH_UNSAFE_CODE = ENV_TOKENS.get("COURSES_WITH_UNSAFE_CODE", [])
 
-############### Mixed Related(Secure/Not-Secure) Items ##########
-# If segment.io key specified, load it and turn on segment IO if the feature flag is set
-SEGMENT_IO_LMS_KEY = AUTH_TOKENS.get('SEGMENT_IO_LMS_KEY')
-if SEGMENT_IO_LMS_KEY:
-    MITX_FEATURES['SEGMENT_IO_LMS'] = ENV_TOKENS.get('SEGMENT_IO_LMS', False)
-
 ############################## SECURE AUTH ITEMS ###############
 # Secret things: passwords, access keys, etc.
 
 with open(ENV_ROOT / CONFIG_PREFIX + "auth.json") as auth_file:
     AUTH_TOKENS = json.load(auth_file)
 
+############### Mixed Related(Secure/Not-Secure) Items ##########
+# If Segment.io key specified, load it and enable Segment.io if the feature flag is set
+SEGMENT_IO_LMS_KEY = AUTH_TOKENS.get('SEGMENT_IO_LMS_KEY')
+if SEGMENT_IO_LMS_KEY:
+    MITX_FEATURES['SEGMENT_IO_LMS'] = ENV_TOKENS.get('SEGMENT_IO_LMS', False)
+
+
 SECRET_KEY = AUTH_TOKENS['SECRET_KEY']
 
 AWS_ACCESS_KEY_ID = AUTH_TOKENS["AWS_ACCESS_KEY_ID"]