Ask HN: Code worth reading

I just graduated with a degree in CS, my school only taught me Java. I'd like to broaden myself first by learning C deeply.

Can anyone suggest any good (C?) code to learn from? Specifically, I would like code that doesn't deal with GUI stuff, and possibly related to networking/os internals. Hopefully something less idiosyncratic than the Linux kernel, because I'm not smart enough to grok any of that really.