micro_httpd is a very small Unix-based HTTP server. It runs from inetd, which means its performance is poor. But for low-traffic sites, it's quite adequate. It implements all the basic features of an HTTP server, including:
All in about 200 lines of code.
micro_httpd can also be used to serve HTTPS by wrapping it with stunnel. Instructions are included.
Other tiny and/or weird web servers (all run from inetd):
ACME Labs / Software / micro_httpd