What is TempleOS?

TempleOS is a biblical-themed lightweight operating system (OS) designed to be the Third Temple prophesied in the Bible. It was created by American programmer Terry A. Davis, who developed it alone over a decade after a series of manic episodes that he later described as a revelation from God.

The system was characterized as a modern x86-64 Commodore 64, using an interface similar to a mixture of DOS and Turbo C. Davis proclaimed that the system's features, such as its 640x480 resolution, 16-color display, and single-voice audio, were designed according to explicit instructions from God. It was programmed with an original variation of C (named HolyC) in place of BASIC and included an original flight simulator, compiler, and kernel.

First released in 2005 as J Operating System, TempleOS was renamed in 2013 and was last updated in 2018.