Lua is used in many products and projects around the world. Here are some highlights. A different selection is shown every day.
The widely popular game Angry Birds is mostly written in Lua. See a talk by Jaakko Lisalo at the Game Design Expo 2011. | Adobe Photoshop Lightroom is mostly written in Lua. Lightroom also supports Lua plug-ins. | 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. | "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) |
Wikipedia uses Lua as its template scripting language. Read the announcement. | Players of World of Warcraft use Lua to customize the game interface. | Nmap, a popular tool for network discovery and security auditing, is scriptable with Lua. | LuaTeX, the engine behind most modern installations of TeX, uses Lua as its embedded scripting language. |