The Beta, tbeta for short, is a open source/cross-platform solution for computer vision and multi-touch sensing. It takes an video input stream and outputs tracking data (e.g. coordinates and blob size) and touch events.
This is a variation of Graffiti Research Lab's L.A.S.E.R Tag ported to the TouchKit.
Touche is a free, open-source tracking environment for FTIR-based multitouch tables.