Ohloh is a quickly growing directory of the world's free software, with a neat twist: it derives interesting statistics and comparisions by inspecting the source code and how it changes over time.
Show your support for the free software you like, by signing up to Ohloh and adding projects to your "stack". This in turn informs other visitors which projects have merit.
While you're there, you can see some interesting statistics about SilverStripe, like the fact it suggests it would take a single person 24 years to write the code. (We've done it in less than 24 months!).
It also creates interesting profiles about the people involved, and a resulting map of supporters.