[saurabhjha]

Some open source projects have "Easy to Fix" issues to get people on the roll (like Scikit-Learn), but many don't.

Some have overview of their source code and their design principles (like Redis) but many don't.

Some have good documentation of how to get your patches in main tree but many (especially those not hosted on github) don't have it.

Most notably for C/C++ projects, the undocumented dependencies to build the library can waste hours at a time.

Open source is great (I have contributed to a couple of projects) but not all projects are equal in terms of quality/easy-to-hack.

Brad Fitzpatrick has also written quite a bit about this http://brad.livejournal.com/2409049.html