Language Details: Lua

Lua is a powerful, fast, lightweight, embeddable scripting language, combining simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics.

Official website (see also: Wikipedia article)
Code Jam 2009 Contestants using Lua
Qualification Round
Used in 7 solutions by 2 contestants:
Round 1A
Used in 2 solutions by 1 contestants:
Round 1B
Used in 4 solutions by 1 contestants:
Round 2
Used in 4 solutions by 1 contestants:

Submission Origin

Japan (1 contestant)
Russia (1 contestant)
Spain (1 contestant)