Here is the OS homepage
https://templeos.org/
I found this OS through a video from Linus Tech Tips. This one doesn’t go through a lot of the detail behind the OS, but does give you a walk through some of its more interesting features.
The video above intrigued me so I decided to see if I could find some more information and ran across this video. Be warned it can be a bit disturbing. It essentially follows the life of the creator who eventually seems to be mentally ill, yet is still develops this OS and incorporates some of the unusual features due to this state.
He created some interesting features in his OS. The 2 I found most interesting are the ASCII file that could incorporate still and animated images, and that the entire OS remains in low level operating mode (Ring 0) leaving you complete access to all of the hardware. I also found the graphics fairly interesting since it is all 16 color it is pretty impressive what he was able to create with just 16 colors. I have not had an opportunity to play around with the OS, let me know if you have used this OS before and what your experience was like.