Here's the main file for relayd, which is a daemon that handles load balancing and failover. It's nicely written, full featured, clean C code. It's big enough that you get a feel for a "real world" program, but not so big that you can't get your head around it with some work. Great for secure, well written networking code, daemons, etc.
Modesty aside, there's also a little tiling window manager for X that I've helped with. It's quite small but it's a real wm, and the other coders on it have high standards (and hold me to them!)... Nice for learning basic X stuff.
