HITs is a link-structure analysis algorithm which ranks pages by "authorities" (pages which have many incoming links and provide the best source of information on a given topic) and "hubs" (pages which have many outgoing links and provide useful lists...

Open source system that provides fully decentralized approximate keyword search capabilities to Vuze as a standard plugin. As it is decentralized, it's immune to legal and technical attacks targeting torrent aggregators.

AsTeR --Audio System For Technical Readings-- is a computing system for rendering technical documents written in LaTeX in audio.

LaTeX Tutorial with examples and exercises.