What is NULLos?

An operating system of its own. Everything written from scratch, everything open, everything in C.

NULLos – no BS. The operating system without the bullshit. (pun intended)

The idea

Building his own operating system – Max had that idea as a little boy. On Tuesday, Oct 28, 2026, around 7:30 pm it finally got going for real. Fifteen minutes later NULLos showed its first prompt in QEMU.

What does “from scratch” mean?

Really everything comes from this repo:

• nb – the bootloader (UEFI)
• nk – the kernel
• libc – its own C library
• cc – its own C compiler, which already compiles itself
• s – the shell, understands Bash scripts
• Hundreds of small tools with very short names
• py – even its own Python interpreter; its test suite runs the same on NULLos as with CPython

No Linux, BSD, Mac or Android base. Only startup code in assembler, the rest is C.

The guidelines

1. As simple as possible. Copying is c quelle ziel. Done.
2. Tab completes everything: commands, options, paths, devices, processes.
3. Core first. Bootloader → kernel → prompt → libc → tools → compiler → Python.
4. Runs everywhere, from the ESP32 to the PC. Making good use of cheap hardware is a main goal.
5. Lots of hardware: NVMe, SATA, USB, keyboard, screen, network later.
6. Design comes later. Text prompt for now.