Fennel is a lisp that compiles to Lua. It aims to be easy to use,
expressive, and has almost zero overhead compared to writing Lua directly.

Features:
- Full Lua compatibility: Easily call any Lua function or library from
  Fennel and vice-versa.
- Zero overhead: Compiled code should be just as efficient as hand-written
  Lua.
- Compile-time macros: Ship compiled code with no runtime dependency
  on Fennel.
- Embeddable: Fennel is a one-file library as well as an executable.
  Embed it in other programs to support runtime extensibility and interactive
  development.