COMP8440 is a graduate-level course on free & open source software (FOSS). Lots of good material here; if you’re interested, you should also look at Karl Fogel’s Producing Open Source Software.

And while I’m posting links: Pierre Lafayette (a non-student working on Basie) sent a link to http://browsershots.org/, which will show you what your web pages look like in a bewildering variety of browsers on various platforms.