Correction: Apple never used X as a native window system, nor did NeXT. The did provide the hooks for an X11 server to run on macOS. From memory this was due to requests from the academic community at the time.

What an incredible project. I also find it tragic how much Apple hates people running software on their devices that makes them vastly more useful.

Neat! I sent you an email about possibly making it work on older versions of iOS.