Based on: KolibriOS
The last version | Released: | 2013
Ostin Project – an operating system based on (and is developed in loose coordination with) KolibriOS.
It offers strict code formatting and commenting guidelines as well as proper documentation. While Kolibri is mostly developed by Russian/ex-USSR community, Ostin tries to be as much international as possible.
Ostin is also strictly assembly-only, just-for-fun operating system.
The project founder is Mike Gelfand.
Ostin kernel source code