I advised a little bit on this project, and so I wanted to give it some more visibility here:
https://github.com/rotorvator/outerscope
It's a MenuQC based menu replacement for Quake, Quake II and Hexen II for those using FTEQW. It tries to be similar to the vanilla menu, but not identical. Things like player colors/skins all work - and it even indexes the maps/* directory for levels and their titles (by reading the worldspawn's .message field)
It also has support for controllers, and displays controller glyphs as well.
This will no doubt be a great reference to anybody wanting to figure out how to get started creating their own menu, or perhaps even use it as a base.
License: MIT license