diff --git a/lms/djangoapps/django_comment_client/base/views.py b/lms/djangoapps/django_comment_client/base/views.py
index 86fe285af0..73cf4a4e27 100644
--- a/lms/djangoapps/django_comment_client/base/views.py
+++ b/lms/djangoapps/django_comment_client/base/views.py
@@ -19,24 +19,22 @@ from django_comment_client.utils import JsonResponse, JsonError
 
 def thread_author_only(fn):
     def verified_fn(request, *args, **kwargs):
-        thread_id = args.get('thread_id', False) or \
-                    kwargs.get('thread_id', False)
+        thread_id = kwargs.get('thread_id', False)
         thread = comment_client.get_thread(thread_id)
-        if request.user.id == thread['user_id']:
+        if str(request.user.id) == str(thread['user_id']):
             return fn(request, *args, **kwargs)
         else:
-            return JsonError(400, "unauthorized")
+            return JsonError("unauthorized")
     return verified_fn
 
 def comment_author_only(fn):
     def verified_fn(request, *args, **kwargs):
-        comment_id = args.get('comment_id', False) or \
-                    kwargs.get('comment_id', False)
+        comment_id = kwargs.get('comment_id', False)
         comment = comment_client.get_comment(comment_id)
-        if request.user.id == comment['user_id']:
+        if str(request.user.id) == str(comment['user_id']):
             return fn(request, *args, **kwargs)
         else:
-            return JsonError(400, "unauthorized")
+            return JsonError("unauthorized")
     return verified_fn
 
 def instructor_only(fn): #TODO add instructor verification
@@ -81,7 +79,7 @@ def delete_thread(request, course_id, thread_id):
     response = comment_client.delete_thread(thread_id)
     return JsonResponse(response)
 
-@thread_author_only
+@comment_author_only
 @login_required
 @require_POST
 def update_comment(request, course_id, comment_id):
diff --git a/lms/djangoapps/django_comment_client/utils.py b/lms/djangoapps/django_comment_client/utils.py
index 30c74c0bb0..ef7ec4d4fc 100644
--- a/lms/djangoapps/django_comment_client/utils.py
+++ b/lms/djangoapps/django_comment_client/utils.py
@@ -100,8 +100,10 @@ class JsonResponse(HttpResponse):
                                            mimetype='application/json; charset=utf8')
 
 class JsonError(HttpResponse):
-    def __init__(self, error_message=""):
-        content = simplejson.dumps({'errors': error_message},
+    def __init__(self, error_messages=[]):
+        if isinstance(error_messages, str):
+            error_messages = [error_messages]
+        content = simplejson.dumps({'errors': error_messages},
                                    indent=2,
                                    ensure_ascii=False)
         super(JsonError, self).__init__(content,
diff --git a/lms/static/coffee/src/customwmd.coffee b/lms/static/coffee/src/customwmd.coffee
index bb22fcc7f2..4c8ee38f36 100644
--- a/lms/static/coffee/src/customwmd.coffee
+++ b/lms/static/coffee/src/customwmd.coffee
@@ -124,10 +124,12 @@ $ ->
         return
 
       if not $elem.find(".wmd-panel").length
+        initialText = $elem.html()
+        $elem.empty()
         _append = appended_id || ""
         $wmdPanel = $("<div>").addClass("wmd-panel")
                    .append($("<div>").attr("id", "wmd-button-bar#{_append}"))
-                   .append($("<textarea>").addClass("wmd-input").attr("id", "wmd-input#{_append}"))
+                   .append($("<textarea>").addClass("wmd-input").attr("id", "wmd-input#{_append}").html(initialText))
                    .append($("<div>").attr("id", "wmd-preview#{_append}").addClass("wmd-panel wmd-preview"))
         $elem.append($wmdPanel)
 
diff --git a/lms/static/coffee/src/discussion.coffee b/lms/static/coffee/src/discussion.coffee
index bb9d7a267c..479c8f69dc 100644
--- a/lms/static/coffee/src/discussion.coffee
+++ b/lms/static/coffee/src/discussion.coffee
@@ -26,7 +26,7 @@ generateDiscussionLink = (cls, txt, handler) ->
 Discussion =
 
   replyTemplate: """
-    <div class="discussion-reply-new">
+    <form class="discussion-reply-new">
       <ul class="discussion-errors"></ul>
       <div class="reply-body"></div>
       <input type="checkbox" class="discussion-post-anonymously" id="discussion-post-anonymously-{{id}}" />
@@ -35,9 +35,32 @@ Discussion =
       <input type="checkbox" class="discussion-auto-watch" id="discussion-autowatch-{{id}}" checked />
       <label for="discussion-auto-watch-{{id}}">watch this thread</label>
       {{/showWatchCheckbox}}
-    </div>
+      <br />
+      <a class="discussion-submit-reply control-button" href="javascript:void(0)">Submit</a>
+      <a class="discussion-cancel-reply control-button" href="javascript:void(0)">Cancel</a>
+    </form>
   """
-  
+
+  editThreadTemplate: """
+    <form class="discussion-content-edit discussion-thread-edit" _id="{{id}}">
+      <ul class="discussion-errors discussion-update-errors"></ul>    
+      <input type="text" class="thread-title-edit title-input" placeholder="Title" value="{{title}}"/>
+      <div class="thread-body-edit body-input">{{body}}</div>
+      <input class="thread-tags-edit" placeholder="Tags" value="{{tags}}" />
+      <a class="discussion-submit-update control-button" href="javascript:void(0)">Update</a>
+      <a class="discussion-cancel-update control-button" href="javascript:void(0)">Cancel</a>
+    </form>
+  """
+
+  editCommentTemplate: """
+    <form class="discussion-content-edit discussion-comment-edit" _id="{{id}}">
+      <ul class="discussion-errors discussion-update-errors"></ul>    
+      <div class="comment-body-edit body-input">{{body}}</div>
+      <a class="discussion-submit-update control-button" href="javascript:void(0)">Update</a>
+      <a class="discussion-cancel-update control-button" href="javascript:void(0)">Cancel</a>
+    </form>
+  """
+
   urlFor: (name, param) ->
     {
       watch_commentable   : "/courses/#{$$course_id}/discussion/#{param}/watch"
@@ -140,15 +163,14 @@ Discussion =
       $local(".thread").each(initializeVote).each(initializeWatchThreads)
       initializeWatchDiscussion(discussion)
 
-    if $$tags?
-      $local(".new-post-tags").tagsInput
-        autocomplete_url: Discussion.urlFor('tags_autocomplete')
-        autocomplete:
-          remoteDataType: 'json'
-        interactive: true
-        defaultText: "add a tag"
-        height: "30px"
-        removeWithBackspace: true
+    $local(".new-post-tags").tagsInput
+      autocomplete_url: Discussion.urlFor('tags_autocomplete')
+      autocomplete:
+        remoteDataType: 'json'
+      interactive: true
+      defaultText: "add a tag"
+      height: "30px"
+      removeWithBackspace: true
 
   bindContentEvents: (content) ->
 
@@ -162,12 +184,6 @@ Discussion =
       status = $discussionContent.attr("status") || "normal"
       if status == "normal"
         $local(".discussion-link").show()
-      else if status == "reply"
-        $local(".discussion-cancel-reply").show()
-        $local(".discussion-submit-reply").show()
-      else if status == "edit"
-        $local(".discussion-cancel-edit").show()
-        $local(".discussion-update-edit").show()
 
     discussionContentHoverOut = ->
       $local(".discussion-link").hide()
@@ -175,9 +191,9 @@ Discussion =
     $discussionContent.hover(discussionContentHoverIn, discussionContentHoverOut)
 
     handleReply = (elem) ->
-      editView = $local(".discussion-reply-new")
-      if editView.length
-        editView.show()
+      $replyView = $local(".discussion-reply-new")
+      if $replyView.length
+        $replyView.show()
       else
         view = {
           id: id
@@ -185,19 +201,16 @@ Discussion =
         }
         $discussionContent.append Mustache.render Discussion.replyTemplate, view
         Markdown.makeWmdEditor $local(".reply-body"), "-reply-body-#{id}", Discussion.urlFor('upload')
-      cancelReply = generateDiscussionLink("discussion-cancel-reply", "Cancel", handleCancelReply)
-      submitReply = generateDiscussionLink("discussion-submit-reply", "Submit", handleSubmitReply)
+        $local(".discussion-submit-reply").click handleSubmitReply
+        $local(".discussion-cancel-reply").click handleCancelReply
       $local(".discussion-link").hide()
-      $(elem).after(submitReply).replaceWith(cancelReply)
       $discussionContent.attr("status", "reply")
 
     handleCancelReply = (elem) ->
-      editView = $local(".discussion-reply-new")
-      if editView.length
-        editView.hide()
-      $local(".discussion-submit-reply").remove()
+      $replyView = $local(".discussion-reply-new")
+      if $replyView.length
+        $replyView.hide()
       reply = generateDiscussionLink("discussion-reply", "Reply", handleReply)
-      $local(".discussion-link").show()
       $(elem).replaceWith(reply)
       $discussionContent.attr("status", "normal")
 
@@ -231,10 +244,76 @@ Discussion =
           Discussion.handleAnchorAndReload(response)
       , 'json'
 
+    handleCancelEdit = (elem) ->
+      $local(".discussion-content-edit").hide()
+      $local(".discussion-content-wrapper").show()
+
     handleEditThread = (elem) ->
+      $local(".discussion-content-wrapper").hide()
+      $editView = $local(".discussion-content-edit")
+      if $editView.length
+        $editView.show()
+      else
+        view = {
+          id: id
+          title: $local(".thread-title").html()
+          body: $local(".thread-raw-body").html()
+          tags: $local(".thread-raw-tags").html()
+        }
+        $discussionContent.append Mustache.render Discussion.editThreadTemplate, view
+        Markdown.makeWmdEditor $local(".thread-body-edit"), "-thread-body-edit-#{id}", Discussion.urlFor('update_thread', id)
+        $local(".thread-tags-edit").tagsInput
+          autocomplete_url: Discussion.urlFor('tags_autocomplete')
+          autocomplete:
+            remoteDataType: 'json'
+          interactive: true
+          defaultText: ""
+          height: "30px"
+          removeWithBackspace: true
+        $local(".discussion-submit-update").unbind("click").click -> handleSubmitEditThread(this)
+        $local(".discussion-cancel-update").unbind("click").click -> handleCancelEdit(this)
+
+    handleSubmitEditThread = (elem) ->
+      url = Discussion.urlFor('update_thread', id)
+      title = $local(".thread-title-edit").val()
+      body = $local("#wmd-input-thread-body-edit-#{id}").val()
+      tags = $local(".thread-tags-edit").val()
+      $.post url, {title: title, body: body, tags: tags}, (response, textStatus) ->
+        if response.errors
+          errorsField = $local(".discussion-update-errors").empty()
+          for error in response.errors
+            errorsField.append($("<li>").addClass("new-post-form-error").html(error))
+        else
+          Discussion.handleAnchorAndReload(response)
+      , 'json'
 
     handleEditComment = (elem) ->
-          
+      $local(".discussion-content-wrapper").hide()
+      $editView = $local(".discussion-content-edit")
+      if $editView.length
+        $editView.show()
+      else
+        view = {
+          id: id
+          body: $local(".comment-raw-body").html()
+        }
+        $discussionContent.append Mustache.render Discussion.editCommentTemplate, view
+        Markdown.makeWmdEditor $local(".comment-body-edit"), "-comment-body-edit-#{id}", Discussion.urlFor('update_comment', id)
+        $local(".discussion-submit-update").unbind("click").click -> handleSubmitEditComment(this)
+        $local(".discussion-cancel-update").unbind("click").click -> handleCancelEdit(this)
+
+    handleSubmitEditComment= (elem) ->
+      url = Discussion.urlFor('update_comment', id)
+      body = $local("#wmd-input-comment-body-edit-#{id}").val()
+      $.post url, {body: body}, (response, textStatus) ->
+        if response.errors
+          errorsField = $local(".discussion-update-errors").empty()
+          for error in response.errors
+            errorsField.append($("<li>").addClass("new-post-form-error").html(error))
+        else
+          Discussion.handleAnchorAndReload(response)
+      , 'json'
+
     $local(".discussion-reply").click ->
       handleReply(this)
 
diff --git a/lms/static/sass/_discussion.scss b/lms/static/sass/_discussion.scss
index a993925a18..4f5c3dd2f1 100644
--- a/lms/static/sass/_discussion.scss
+++ b/lms/static/sass/_discussion.scss
@@ -48,7 +48,7 @@ $discussion_input_width: 85%;
       margin-top: flex-gutter(8);
     }
   }
-  
+
   .discussion-title {
     @include discussion-font;
     @include discussion-clickable;
@@ -104,16 +104,16 @@ $discussion_input_width: 85%;
     float: left;
     width: 70%;
   }
-  .new-post-form {
-    .new-post-title, .new-post-body {
+  .new-post-form, .discussion-thread-edit {
+    .title-input, .body-input {
       @include discussion-font;
       display: block !important;
       width: $discussion_input_width !important;
     }
-    .new-post-body {
+    .body-input {
       margin-top: 10px;
     }
-    .discussion-new-post {
+    .control-button {
       @include discussion-font;
       color: #1d9dd9;
       display: block;
@@ -127,6 +127,12 @@ $discussion_input_width: 85%;
       height: 100%;
     }
   }
+  .discussion-content-edit, .discussion-reply-new {
+    .control-button {
+      display: inline-block;
+    }
+    margin: 10px 0 10px 0;
+  }
   .thread {
     //display: none;
     margin-top: 30px;
diff --git a/lms/templates/discussion/inline.html b/lms/templates/discussion/inline.html
index dbd34305c3..42fac4e110 100644
--- a/lms/templates/discussion/inline.html
+++ b/lms/templates/discussion/inline.html
@@ -8,10 +8,10 @@
     ${search_bar}
     <form class="new-post-form" _id="${discussion_id}">
       <ul class="discussion-errors"></ul>    
-      <input type="text" class="new-post-title" placeholder="Title"/>
-      <div class="new-post-body"></div>
+      <input type="text" class="new-post-title title-input" placeholder="Title"/>
+      <div class="new-post-body body-input"></div>
       <input class="new-post-tags" placeholder="Tags"/>
-      <a class="discussion-new-post" href="javascript:void(0)">New Post</a>
+      <a class="discussion-new-post control-button" href="javascript:void(0)">New Post</a>
     </form>
   </div>
   % for thread in threads:
diff --git a/lms/templates/discussion/thread.html b/lms/templates/discussion/thread.html
index c72bb5aad0..97b71b8364 100644
--- a/lms/templates/discussion/thread.html
+++ b/lms/templates/discussion/thread.html
@@ -28,12 +28,13 @@
 
 <%def name="render_content(content, type, **kwargs)">
   <div class="discussion-content">
-    <div class="discussion-upper-wrapper clearfix">
+    <div class="discussion-content-wrapper clearfix">
       ${render_vote(content)}
       <div class="discussion-right-wrapper clearfix">
         ${render_title(content, type, **kwargs)}
         <div class="discussion-content-view">
           <div class="content-body ${type}-body">${content['body'] | h}</div>
+          <div class="content-raw-body ${type}-raw-body" style="display: none">${content['body'] | h}</div>
           ${render_tags(content, type, **kwargs)}
           ${render_bottom_bar(content, type, **kwargs)}
         </div>
@@ -63,9 +64,10 @@
   % if type == "thread":
     <div class="thread-tags">
       % for tag in content['tags']:
-        <a class="thread-tag" href="${url_for_tags([tag])}">${tag}</a>
+        <a class="thread-tag" href="${url_for_tags([tag])}">${tag | h}</a>
       % endfor
     </div>
+    <div class="thread-raw-tags" style="display: none">${tag | h}</div>
   % endif
 </%def>