diff --git a/scripts/summarize_test_results.py b/scripts/summarize_test_results.py
new file mode 100755
index 0000000000..32f1879ed4
--- /dev/null
+++ b/scripts/summarize_test_results.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+"""Summarize the results of running all the tests.
+
+See the report_all_files docstring for details, or run this with --help.
+
+"""
+
+import collections
+import os
+
+import click
+from lxml import etree
+
+
+@click.command()
+@click.option("--errors/--no-errors", help="Show details of errors")
+@click.option("--names/--no-names", help="Show all test names")
+@click.option("--outcomes/--no-outcomes", help="Show pass/fail/error with names")
+@click.argument("start", default="reports")
+def report_all_files(errors, names, outcomes, start):
+    """Find all the nosetests.xml files, and report on them.
+
+    For every nosetests.xml file found, prints a summary of the number of
+    tests, fails, errors, etc.  If --details is used, then the error messages
+    from all of the fails and errors will be shown, most frequent first, with a
+    count of how many tests failed for that reason.
+
+    """
+    totals = TestResults()
+    for dirpath, _, filenames in os.walk(start):
+        if "nosetests.xml" in filenames:
+            results = report_file(
+                os.path.join(dirpath, "nosetests.xml"),
+                errors=errors,
+                names=names,
+                outcomes=outcomes,
+            )
+            totals += results
+
+    print "\nTotals:\n{}".format(totals)
+
+
+class Summable(object):
+    """An object whose attributes can be added together easily.
+
+    Subclass this and define `fields` on your derived class.
+
+    """
+    def __init__(self):
+        for name in self.fields:
+            setattr(self, name, 0)
+
+    @classmethod
+    def from_element(cls, element):
+        """Construct a Summable from an xml element with the same attributes."""
+        self = cls()
+        for name in self.fields:
+            setattr(self, name, int(element.get(name)))
+        return self
+
+    def __add__(self, other):
+        result = type(self)()
+        for name in self.fields:
+            setattr(result, name, getattr(self, name) + getattr(other, name))
+        return result
+
+
+class TestResults(Summable):
+    """A test result, makeable from a nosetests.xml <testsuite> element."""
+
+    fields = ["tests", "errors", "failures", "skip"]
+
+    def __str__(self):
+        msg = "{0.tests:4d} tests, {0.errors} errors, {0.failures} failures, {0.skip} skipped"
+        return msg.format(self)
+
+
+def error_line_from_error_element(element):
+    """Given an <error> element, get the important error line from it."""
+    return element.get("message").splitlines()[0]
+
+
+def report_file(path, errors, names, outcomes):
+    """Report on one nosetests.xml file."""
+    print "\n{}".format(path)
+    with open(path) as xml_file:
+        tree = etree.parse(xml_file)                # pylint: disable=no-member
+    suite = tree.xpath("/testsuite")[0]
+
+    results = TestResults.from_element(suite)
+    print results
+
+    if errors:
+        errors = collections.Counter()
+        for error_element in tree.xpath(".//error|.//failure"):
+            errors[error_line_from_error_element(error_element)] += 1
+
+        if errors:
+            print ""
+            for error_message, number in errors.most_common():
+                print "{0:4d}: {1}".format(number, error_message)
+
+    if names:
+        for testcase in tree.xpath(".//testcase"):
+            if outcomes:
+                result = testcase.xpath("*")
+                if result:
+                    outcome = result[0].tag
+                    if outcome == "system-out":
+                        outcome = "."
+                    else:
+                        outcome = outcome[0].upper()
+                else:
+                    outcome = "."
+            else:
+                outcome = ""
+            print "  {outcome} {classname}.{name}".format(
+                outcome=outcome,
+                classname=testcase.get("classname"),
+                name=testcase.get("name"),
+            )
+
+    return results
+
+
+if __name__ == "__main__":
+    report_all_files()                  # pylint: disable=no-value-for-parameter