Touchlib is a library for creating multi-touch interaction surfaces. It handles tracking blobs of infrared light, and sends your programs these multi-touch events, such as 'finger down', 'finger moved', and 'finger released'. It includes a configuration app and a few demos to get you started, and will interace with most types of webcams and video capture devices. It currently works only under Windows but efforts are being made to port it to other platforms. For a cross platform version try Community Core Vision

One of the first open-source libraries created to support multi-touch hardware and software, Touchlib has helped to bring multi-touch to the the main stream developer community. They have a large, active community of users and developers that are involved in a variety of interesting touch related projects.

Community Core Vision or CCV for short (also known as tbeta), is a open source/cross-platform solution for computer vision and machine sensing. It takes an video input stream and outputs tracking data (e.g. coordinates and blob size) and events (e.g. finger down, moved and released) that are used in building nui aware applications. CCV can interface with various web cameras and video devices as well as connect to various TUIO/OSC/XML enabled applications and supports many multi-touch lighting techniques including: FTIR, DI, DSI, and LLP with expansion planned for the future vision applications (custom modules/filters).

Out of the Touchlib community comes a new and improved multi-touch library. Although still in Beta, CCV is compatible with the Demand Evolution screens and it provides a number of improvements in touch performance and accuracy.

reacTIVision is an open source, cross-platform computer vision framework for the fast and robust tracking of fiducial markers attached onto physical objects, as well as for multi-touch finger tracking. It was mainly designed as a toolkit for the rapid development of table-based tangible user interfaces (TUI) and multi-touch interactive surfaces.

PyMT is a python module for developing multi-touch enabled media rich applications. Currently the aim is to allow for quick and easy interaction design and rapid prototype development.

Multi-touch libraries for the Processing system.

A multi-touch library for Max/MSP created by Mathieu Chamagne. This library requires that a TUIO server be running locally, serving touch events.

This framework consists of a set of Max abstractions. To 'multitouchize' a patch, you just need to place an <> abstraction in your patch, and add to presentation mode and give a name to all the UI objects that you wish to control with your multitouch screen, and that�s all! MMF will do the rest.

Multi-touch support for Windows WPF framework.

Multi-touch support for Windows Vista.

Know about a multi-touch project?

If you know about a multi-touch related project that we should include here, let us know and we'll add it to the list.