What open source projects are you contributing to?

These days it is probably a given thing that hackers should contribute to open source projects to hone their skills. Except for the odd bug report, I still haven't found the time, as currently I don't even manage my own projects very well.

I would be curious though, what projects are you contributing to, and how did you get started? Are people more likely to start their own projects, or join existing ones?

For what it is worth, I consider open sourcing my unpublished mobile games, most notably a "who wants to be a millionaire" style quiz game. Perhaps if somebody else would be interested, I could work up the motivation to do so...