Heh, you beat me to publishing my own simple HTTP server. Though the one I'm working on is even more dumbed down, only supporting GET to serve prepared HTTP messages from a hash table (this requires a creative interpretation of RFC 7230 to avoid including the Date header which would have to be updated each time).

I very much approve of this tutorial, I remember when long time ago I tried to understand how a web server works, and learned that I need to install Apache, then put stuff in CGI directory, or maybe just use a framework and not have a separate server at all... It was quite confusing for me back then. But the core functionality of a HTTP server is just listen on a port, accept connections, read text, write text.

For anyone interested, I also recommend to read "Unix Network Programming" books; the first part is about actual network programming, the second about inter-process communication on a single computer. For example, the old art of using Unix-domain sockets for TCP or UDP on a single computer (harder to hack by shady javascript in your browser!) seems unjustly forgotten.