Mizu.

A small desktop operating system with a 90s soul, on a kernel written from nothing. These pages are how to install it, live in it, and write programs for it.

The SDK, ready to use: mizu-sdk.tar.gz (about 28 MB, SHA-256). koicc, koi-gcc and the C library with zlib, libpng, libjpeg, expat, FreeType, Mbed TLS, curl and FFmpeg already built. Unpack it anywhere on Linux with GCC and see Porting software.

InstallingA USB stick, a virtual machine, or a disk next to Windows. Using MizuThe desktop, keys worth knowing, updates, and what to do when something breaks. Translating MizuOne text file per language, and how to check it. Writing a programThe SDK, koicc, files, graphics, sound, network and threads. Porting softwaremusl, koi-gcc and configure: bringing C programs from elsewhere. Writing an appWindows on the Mizu desktop: MIZU_APP, MIZU_API and how an app lives. Packagesdosget, manifests, and how a program reaches the Start menu. System callsEvery call, its number and its wrapper, generated from the headers.

What Mizu is

Mizu (水, water) is a desktop system for x86-64 UEFI PCs: overlapping windows, a Start menu, a web browser, a music and video player, card games, notifications and screenshots, a package manager and an App Store, in six languages and counting. It runs on kernel MX 27, grown from Koi-DOS, the DOS-like system it started as. ver shows both.

Programs, the command prompt and the package manager run in ring 3, each in its own memory: a crash ends that program, not the machine.
The system is a read-only image in one of two slots. An update goes into the other one, and if it does not start three times, Mizu goes back by itself.
It uses every processor core, its own file system (KFS) for the system disk, and FAT32 for USB sticks.

Installing →