Erlang Creative Forum (ECF)
Simple BEAM-powered forum software
ECF is forum software that I've written from scratch in Erlang. It uses the Cowboy webserver, but beyond that all of the core logic was written by me. It's still very unfinished, but you can take a look at it at the "ECF" link above. The code is available on GitHub if you would like to take a look at it, or use it yourself.