mruby is the lightweight implementation of the Ruby language complying to the ISO standard. mruby can run Ruby code in 'interpreter mode' or 'compile and execute it on a virtual machine' depending on the developer's preference.
This achievement was sponsored by the Regional Innovation Creation R&D Programs of the Ministry of Economy, Trade and Industry of Japan.
The list of platforms/toolchains on which mruby is known to compile (or not) is available here.
In 2014-01-31, mruby Forum has reelased stable version(v1.0.0) of mruby.
Mruby Forum is a non-profit organization to maintain, educate and promote mruby. (http://forum.mruby.org/)