Lua is a powerful, fast, lightweight, embeddable scripting language. It is heavily used in the game industry and security tools such as Wireshark, Snort, nmap also make use of it.
The language combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. Lua is dynamically typed, runs by interpreting bytecode for a register-based virtual machine, and has automatic memory management with incremental garbage collection, making it ideal for configuration, scripting, and rapid prototyping.
More information is available at the official website at http://www.lua.org.
More About the Lua Language