A meta compilation framework à la Meta-II by Val Schorre, now for Ruby. Bootstrapped from a pure-C implementation of Meta-II but then self-hosting. A main attraction is that the core specification file is very short (~26 lines), and fully self-contained (both syntax and semantics in s single file) which makes it easy for Rubyists to get into the wonderful world of meta compilation. See github homepage for details and examples: https://github.com/robertfeldt/meta_compile