[kodachi]

Adding to all what been said, the first thing I do is to count the lines of code using cloc, and see the contributors list. There is generally one key person who has the most commits, so it's good to know that person philosophy and style. For example, for reading the redis source code, I learned a lot from its creator blog posts and the redis manifesto (http://oldblog.antirez.com/post/redis-manifesto.html). By the way, I love Redis' style.