Adam Chalmers:

Over the last few weeks I built my own DNS client. Mostly because I thought dig was kinda clunky. Partly because I wanted to learn more about DNS. So here’s how I built it, and how you can build your own too. It’s a great weekend project, and I learned a lot from finishing it.

DNS is simple enough that you can grok it quickly, but still complex enough that Adam learned a ton along the way: reading RFCs, network sockets, Bitvec, and more.