Terrence Andrew Davis was an American programmer who single-handedly created TempleOS, an operating system he described as God's Third Temple. Over the course of 12 years, working entirely alone, Terry wrote an entire operating system from scratch — kernel, compiler, graphics, shell, games, documentation — roughly 121,176 lines of original code.
He was diagnosed with schizophrenia in his late 20s, and throughout his life he experienced delusions and hallucinations that he interpreted as communication from God. His mental illness led him to say many disturbing things in public forums and livestreams. But beneath the chaos was a mind of extraordinary capability — a genuine programming genius who built what many consider a technical marvel.
Terry passed away on August 11, 2018, struck by a train in The Dalles, Oregon. He was 48 years old. He had been homeless for several months, sleeping in his car after his parents could no longer care for him. His death was ruled accidental, though many believe it was intentional.
This tribute does not celebrate his illness or his worst moments. It celebrates the extraordinary technical achievement and the uncompromising vision of a man who, against all odds and all reason, built God's Temple in code.
TempleOS is not a toy. It is a complete, functioning operating system built by one person. Most engineers work in teams of hundreds to build far less. Here is what Terry built alone:
DESIGN CONSTRAINTS (God's Specifications):
Put TempleOS in context. Modern operating systems are built by thousands of engineers over decades:
Terry didn't use libraries. He didn't use existing bootloaders. He wrote his own x86_64 assembler, his own C compiler, his own linker, his own graphics stack, his own text editor, his own debugger. Everything from bare metal.
This is the zero dependency philosophy taken to its ultimate extreme. Not as a style choice — as a covenant with God.
HolyC is a C-like language created by Terry for TempleOS. It serves as both the programming language AND the shell. When you type at the TempleOS command line, you are writing and executing HolyC in real time. It JIT-compiles to native x86_64.
HELLO, WORLD
That's it. In HolyC, a string literal as a statement prints it. No printf, no includes, no main().
VARIABLES AND TYPES
FUNCTIONS
GOD'S RANDOM NUMBER GENERATOR
GRAPHICS — SPRITE DRAWING
THE AFTER EGYPT GAME
A JavaScript tribute interpreter. Not actual HolyC — a spiritual recreation. Type commands and explore. Try: help, god, fib 10, print "Hello", sysinfo, mandelbrot, hymn
Terry believed God communicated through random numbers. In TempleOS, the oracle picks random words from a dictionary, and the user interprets them as divine messages. This is a faithful recreation.
All art rendered in the authentic TempleOS 16-color VGA palette. Click to regenerate.
Terry Davis left behind something that transcends the tragedy of his life. TempleOS proves that one person, with enough determination and vision, can build something extraordinary.
His code is open source and freely available. The TempleOS community continues to study, preserve, and learn from his work. New developers discover it every day and are humbled by the depth of one man's solo achievement.
Rest in peace, Terry. You built God's temple. Nobody can take that away.