KolibriOS is an impressively small yet powerful operating system that requires only minimal disk space and RAM to run. It offers a wide range of applications including a word processor, image viewer, graphical editor, web browser, and numerous games. It also supports various file systems and has drivers for popular sound, network, and graphics cards. What makes KolibriOS stand out is its lightning-fast boot time and instant application startup. This speed is achieved because the kernel and drivers are all written in FASM assembly language. KolibriOS originated from MenuetOS and has been independently developed since 2004. The code is open-source, with most of it released under the GPLv2 license. Feedback and contributions are highly valued.
https://kolibrios.org/en/index.htm