Personally (and I don't think I'm alone in this), I find it quite difficult to read a codebase top to bottom to 'understand' it. Someone else's code, no matter

Personally (and I don't think I'm alone in this), I find it quite difficult to read a codebase top to bottom to 'understand' it. Someone else's code, no matter how good it is written, is difficult to grok without context. To answer you question directly: the best way I've come across to become acquainted with any project is to find an issue that causes you a problem (or one you at least find interesting), and dig in from there. You'll read the codebase in a more directed manner this way. And hey, you may even find the bug! Check out the 'good first issue' flags on some of the popular repos you like. Usually they will have a good deal of background about what the problem is, so you can dive right in.