review-board.org – Web Based Software for Code Reviews

[url=http://review-board.org/]Review Board[/url] is an open source tool developed by the VMware team to help with code reviews and pending code changes. Somewhat similar to an issue tracker, but worth a look.
From the same team: [url=http://chipx86.github.com/gtkparasite/]Parasite[/url], a live debugger for GTK+ applications (“sort of like Firebug”).