Via Marc Hedlund's post on O'Reilly Radar, here's an open source code review tool from VMWare: ReviewBoard. For all of us non-googlers out there, it's probably the next best thing to Guido's Mondrian (question: why has that tool not been released as open source?). Check out the sweet screenshots. The kicker though is that it uses Python and Django. Way to go, VMWare!