TempleOS is somewhat of a legend in the operating system community. Its sole author, Terry A. Davis, has spent the past 12 years attempting to create a new operating from scratch. Terry explains that God has instructed him to construct a temple, a 640×480 covenant of perfection. Unfortunately Terry also suffers from schizophrenia, and has a tendency to appear on various programming forums with a burst of strange, paranoid, and often racist comments. He is frequently banned from most forums.
This combination of TempleOS’s amateurish approach and Terry’s unfortunate outbursts have resulted in TempleOS being often regarded as something to be mocked, ignored, or forgotten. Many people have done some or all of those things, and it’s understandable why.
Perhaps we should instead look at TempleOS as a research operating system: what can be accomplished if you’re not locked into established thinking, backwards compatibility, and market demands.
What can we learn if we are only willing to listen?
I've been meaning to link to TempleOS for some time now. It's not pretty. It's written in its own language (loosely based on C). And it's programmer is schizophrenic. Which is a shame, since the resulting software is impressive.
Sure, it might not be easy to use for a normal user, but as a programmer? All code (and everything is written in HolyC, with just a smattering of assembly) instantly crosslinked and documented. Images and sounds are directly embedded in the source code. There really is no distinction between the shell, the text editor and anything else, really.
The last time software was built like this was in research labs in the 60s and 70s. TempleOS is an impressive piece of work for one man. Everything was written from scratch. And there exist a ton of online video tutorials on how it works (that is, if you can watch them—I find it difficult to watch for more than a few minutes as Terry is not easy to listen to, and it's often hard to follow what, exactly, is going on since the operating system is so out there).