I would argue that the need is project-dependent. Personally, I don't write them. However, if there are more than two of us working on Hubski, it's possible that I'll change that approach. Even so, familiarity with the code is what matters most when you are going to change it, and comments could give a false sense of familiarity, or could be misread. I previously programmed in Fortran with a professor that didn't comment. The code was terse, dense, and was expressing models of phase-transitions. Still, comments would have pretty much been a waste of time in that project. When I could read the code, it meant that I could meaningfully contribute. That said, I've never programmed in a large group. I suppose that if I did, I might comment. But, I don't use my phone's calendar because I forget to enter things. Commenting would take some serious discipline for me. I wonder what akkartik thinks of my commit comments. :)