Enzyme
Enzyme is based on the backend engine developed for the commercial web site CatalystRecruiting.com. It's a system for gathering data so that it can be searched according to specific pre-arranged criteria. For instance, CatalystRecruiting.com collects college students' resume data in a structured way; employers then do searches based on specific criteria (skills, school, GPA, SAT score, etc). The system has a wide range of potential applications for any type of database-related projects including Generic DB-backed "people finding people" application, like CR, eBay, Garage.com, or even SourceForge.