KolibriOS is an open source operating system with a monolithic preemptive kernel, video drivers, for 32-bit x86 architecture computers, developed and maintained by The KolibriOS Project Team. KolibriOS is a fork of MenuetOS, written entirely in FASM (assembly language). However, C, C++, Free Pascal, Forth, among other high-level languages and compilers, can also be used in user application development. English, Russian and German versions are available.