Lua is used in many products and projects around the world. Here are some highlights. A different selection is shown every day.

World of Warcraft LuaTeX Wikipedia LÖVE Players of World of Warcraft use Lua to customize the game interface. LuaTeX, the engine behind most modern installations of TeX, uses Lua as its embedded scripting language. Wikipedia uses Lua as its template scripting language. Read the announcement. LÖVE is a free framework for making 2D games in Lua. Grim Fandango Solar2D Angry Birds Nmap "Grim Fandango was the first game that shows Lua could not only be used to make a good game, but that it could be used to make some of the best games ever." (cited here; see also this) Solar2D is a free Lua based game engine with focus on ease of iterations and usage. It is a fork of the well established and widely used Corona SDK game engine. The widely popular game Angry Birds is mostly written in Lua. See a talk by Jaakko Lisalo at the Game Design Expo 2011. Nmap, a popular tool for network discovery and security auditing, is scriptable with Lua.