https://github.com/madame-rachelle/raspzdoom
This is currently completely based on drfrag666's legacy port of GZDoom. I haven't done anything other than that on it, yet. The point of this is, in conjunction with the legacy port, keep support for the Raspberry Pi alive for GZDoom.
Currently, the only real future plan is to resurrect the pure-SDL implementation of the software renderer, if possible, but otherwise keep it updated with both drfrag666's features and with regular ZScript features in the main GZDoom version. In its current form, though, both hardware acceleration must be enabled, and the use of X11 are required for it to work.
My motivation for this is, I have a pi that I am using as a gaming unit when my niece and nephew comes over to visit. It's mainly useful for playing Chex Quest on, and obviously my favoured port of choice for that is GZDoom. I am sure there are other uses for it in the future, but for now, this port will be exclusively focused for the Raspberry Pi.
Credit goes to drfrag666 for providing the basis for this.