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TempleOS Basics


TempleOS is an operating system designed by Terry Davis ( - ). Davis designed TempleOS for two purposes: first, as a modern-day successor to the Commodore 64 computer, and second, to be the Third Temple prophesized in Judaism and Christianity.

The Commodore 64, or C64, was a personal computer released in , and is the best-selling computer of all time, with over 12 million units sold. C64 programs were written in BASIC, a programming language with a large user base, and an open hardware design that was readily accessed by the user. Both of these qualities made it easy for users to learn and experiement with the C64. The C64’s simplicity made it easy for programmers to take risks and learn from mistakes. Terry Davis hoped TempleOS would fill a similar need, with the added power of modern 64-bit processors. TempleOS would be a simple, open operating system that encouraged programming for fun.

Terry Davis attributed many aspects of TempleOS to divine revelation. Davis wanted people to use TempleOS to communicate with God, and to create offerings for God, in the form of drawings. TempleOS can generate sentences from randomly-selected words, and Davis saw this as a virtual form of speaking in tongues. Another program writes randomly-generated hymns, and another is a simulation based on the Book of Exodus. This religious aspect of TempleOS became more important to Terry Davis as the project neared completion.

TempleOS is remarkable because it is the work of one person. Most operating systems are developed by teams of hundreds of people, or in the case of GNU/Linux, thousands of volunteers; TempleOS was developed by Terry Davis over a period of several years. It is a testament to one man’s ambition and commitment to a goal.


TempleOS was designed specifically for 64-bit, x86 processors. Graphics are limited to 16 colors, at a resolution of 640x480. Audio is limited to a single speaker. There is no support for networking, graphics cards, printers, or any I/O besides PS/2.

In TempleOS, everything happens at the very lowest level of the operating system, known as Ring0. There are no user permissions of any kind.

TempleOS uses a dialect of C called HolyC. In TempleOS, HolyC programs are compiled one line at a time, rather than compiled to binary all at once. This is called JIT (just-in-time) compiling, and makes HolyC similar to an interpreted language like BASIC.

HolyC has features not found in any other operating system. In particular, it is possible to include hyperlinks and sprites within source code. A program that puts graphics on the screen is far easier to write with HolyC and TempleOS than in C or C++. In most other operating systems, there are one or more languages for writing applications, and another language for using the command line, but in TempleOS they are one and the same: HolyC is used for both.

TempleOS is in the PUBLIC DOMAIN. Unlike other free software or open-source licenses like the GPL or the MIT License, there are no legal restrictions on the TempleOS code whatsoever. Terry Davis had some philosophical restrictions on TempleOS, for example, he did not want third-party libraries added to the operating system.


Terry Davis did not design TempleOS to be a person’s primary operating system. It was always intended to be run in an emulator like VirtualBox, or on a dual-boot system alongside Windows or GNU/Linux. Davis imagined a person using TempleOS for their recreational programming projects or religious rituals, and another operating system for their mission-critical applications.