In my opinion you can learn a lot following the development process of Mongrel2. Mongrel2 is a redesign of Mongrel web server and it is a project that have as goal to provide an application, language, and network architecture agnostic web server.

This is probably the most interesting project that I could find right now on the web, because it is under heavy development, it is using new concepts and ideas, it is written in C (very clear and legible code if you ask me), the development process is totally in the open, and this could benefit many people if successfully achieve its goal.

Because of that, and because of the very big bold goal of this project I'm following its progress, I'm testing it and I plan to contribute with Mongrel2 if possible. By now, I'm only contributing from the distribution side of things, so I prepared some packages necessary to test Mongrel2 in Debian (despite Mr. Zed Shaw is very critic of the ``slowness'' of Linux distributions picking new software).

Anyway, below are some links to binary and source packages for Mongrel2 and a couple of dependencies, if anyone besides me is interested in testing this in Debian (or Ubuntu). I already asked for review to have those packages included officially in Debian.