This web content provides a list of various tools for the X Window System, some of which are more obscure than others. The author notes that all applications have been tested on FreeBSD but should also run on other Unix-like operating systems. The content provides short descriptions and installation instructions for each tool. Some highlights include a 3D version of the game “Pong,” a roguelike game based on J.R.R. Tolkien’s books, an emulator for the HP-15C calculator, and a crystalline structure visualization program. The content also mentions that some tools may be prone to crashing or contain bugs.
https://cyber.dabamos.de/unix/x11/