Link to Tulip repo.

pep-3156.txt

@@ -17,7 +17,8 @@ Python 3.3.  Consider this the concrete proposal that is missing from
 PEP 3153.  The proposal includes a pluggable event loop API, transport
 and protocol abstractions similar to those in Twisted, and a
 higher-level scheduler based on ``yield from`` (PEP 380).  A reference
-implementation is in the works under the code name tulip.
+implementation is in the works under the code name Tulip (the Tulip
+repo is linked from the References section at the end).
 
 
 Introduction
@@ -1027,6 +1028,8 @@ References
 - PEP 3153, while rejected, has a good write-up explaining the need
   to separate transports and protocols.
 
+- Tulip repo: http://code.google.com/p/tulip/
+
 - Nick Coghlan wrote a nice blog post with some background, thoughts
   about different approaches to async I/O, gevent, and how to use
   futures with constructs like ``while``, ``for`` and ``with``: