Xapian is a search engine library, scalable to collections containing hundreds of millions of documents. It's written in C++ with bindings for Perl, Python, PHP, Java, Tcl, C#, Ruby, and Lua. It is a highly adaptable toolkit that allows developers to easily add advanced indexing and search facilities to their own applications. It supports the Probabilistic Information Retrieval model and also a rich set of boolean query operators. Omega is a Web search application built upon the Xapian library. It can index a Web server's document tree (including HTML, PDF, OpenOffice, MS Word/Excel/Powerpoint/Works, WordPerfect, RTF, PS, etc.), or data exported from arbitrary sources (e.g. SQL databases).
The Crate Game Engine is a game engine that is designed to make creating games trivial. The rendering and scripting engines are removed from the game engine to make the specialization of games as easy as possible. Currently, scripting support is implemented to allow a Lua script to be put directly in the game file, which can be validated as XML. Multiplayer text based adventure-style games can be played with the existing console rendering engine.
World Domination is a real-time strategy game that uses the Stratagus engine and was inspired by the Axis and Allies board game. It is unique amoung RTSes because it does not require you to havest resources. Instead, you receive money based on how much territory you occupy. This allows the focus of the game to be on combat and not the management of workers.
The aim of LucED is to be a fast and responsive X11 text editor with a simple but powerful user interface similar to NEdit. It uses Lua as an embedded scripting language, and features syntax highlighting that is configurable via PCRE regular expressions with arbitrarily nested patterns.
Excalibur: Morgana's Revenge (EMR) is a first-person shooter game with an epic and in-depth story line. The player travels through time in the Jurassic period, Camelot period, and into the future to chase down Morgana. Using the Aleph One engine, EMR creates an amazing new world, making it an entirely fun and unique gaming experience.
wmluabutton is a general purpose dockapp that is scriptable with lua. It can load and display xpm images at runtime, detect mouse clicks on the images, and can check and update the state regularly. It is intended as a dockapp for X window managers such as Window Maker, AfterStep, BlackBox, and Enlightenment.