reacTIVision is a computer vision framework for the fast and robust tracking of markers attached on physical objects, and the creation of multi-touch surfaces. It was designed for the rapid development of table-based tangible user interfaces.
DigEnv is the implementation of various approaches to digital interactive environments, systems and projects, like multi-touch tables, interactive projections and non-conventional input methods.
MMP is a program/framework designed to process motion data delivered by - for example - a wiimote. The design is modular, so you can adapt it to your own needs.