Lua is minimalistic, lightweight and embeddable scripting language. It’s being designed, implemented, and maintained by a team at PUC-Rio, the Pontifical Catholic University of Rio de Janeiro in Brazil. The mailing list is open to get involved.
Common use-cases for Lua includes scripting video games, extending applications with plugins and configs, wrapping some high-level business logic or just embedding into devices like TVs, cars, etc.
For high performance tasks there is independent implementation using just-in-time-compiler available called LuaJIT.