The OS has not been open sourced yet but will be soon. Personally there is
https://github.com/ThomasHintz/ and
https://bitbucket.org/thomashintz/ and even more on my personal website
http://thintz.comTechnically it could support C. One of the reasons it is based on Scheme though is that there is a lot of code already, code written in Scheme. :)
