I also came across a reddit topic stating that GZDoom might not be able to work on our RPI due to either poor OpenGL support or performance. I will look into making it build the latest stable version 3.0. I was able to compile Zandronum by following the french site, but unfortunately it builds an 3.1 alpha version instead of the latest primary version 3.0 in which Windows users uses. It certainly works both in X11 and Framebuffer. Now that it comes to mind my, it might have been Zandronum that i was successful at compiling earlier.
