use system mathjax

gistfile1.txt

diff --git a/IPython/frontend/html/notebook/notebookapp.py b/IPython/frontend/html/notebook/notebookapp.py
index e7a00c0..7b60934 100644
--- a/IPython/frontend/html/notebook/notebookapp.py
+++ b/IPython/frontend/html/notebook/notebookapp.py
@@ -105,6 +105,11 @@ class NotebookWebApplication(web.Application):
             (r"/notebooks/%s" % _notebook_id_regex, NotebookHandler),
             (r"/rstservice/render", RSTHandler)
         ]
+
+        if os.path.exists("/usr/share/javascript/mathjax/MathJax.js"):
+          handlers.append((r"/mathjax/(.*)", web.StaticFileHandler,
+                           {"path": "/usr/share/javascript/mathjax"}))
+
         settings = dict(
             template_path=os.path.join(os.path.dirname(__file__), "templates"),
             static_path=os.path.join(os.path.dirname(__file__), "static"),
@@ -265,7 +270,10 @@ class NotebookApp(BaseIPythonApplication):
         if not self.enable_mathjax:
             return u''
         static_path = os.path.join(os.path.dirname(__file__), "static")
-        if os.path.exists(os.path.join(static_path, 'mathjax', "MathJax.js")):
+        if os.path.exists("/usr/share/javascript/mathjax/MathJax.js"):
+            self.log.info("Using system MathJax")
+            return u"mathjax/MathJax.js"
+        elif os.path.exists(os.path.join(static_path, 'mathjax', "MathJax.js")):
             self.log.info("Using local MathJax")
             return u"static/mathjax/MathJax.js"
         else: