Which open source project would you recommend contributing to?
language-agnostic, open-source
Solution
Trying to pick a project like that will never work because it's not something you're passionate about. What's an open source project that you use daily or enjoy using? Go work with that one.
Problem
What open source projects would you recommend as a good place for a starting open source developer? Factors that I think would be important are some obvious ones like well written code and a community that is helpful to newbies. But it might be nice if the code base is such that I can start hacking some small problems without really understanding the details of how everything works. I'd prefer something that can be developed on Linux using C/C++/Java/Python/Scala.