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 640x480 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.
You really have no excuse to not read this article.