The title express my intention. I want to see the code of a big project that can be considered a good example of good code writing (clean code, modularization, comments, etc.)

I don't want to know if the tool is good or not, but only how the code IS.

There is some project that can be used as example?

I'm asking this because must great projects have their flaws, some pieces or entire code that appears to be writing to a new person presented to system development (I think that maybe everyone do this in some part of their projects).