Touchsmart TUIO is a free, open-source TUIO bridge application for Nextwindow API-compatible touchscreens such as the ones being used on HP Touchsmart PCs. Even though it runs on Windows XP/Vista, it is based on code from Touché, a free, open-source multitouch tracking environment for optical multitouch table under MacOS X.
The application uses the Nextwindow-supplied API to talk to the touchscreen and translates the tracking information into TUIO, which is a widely-adopted tracking data protocol for optical table-top tracking solutions. It is being used by many multitouch applications.
Using Touchsmart TUIO, TUIO clients can receive tracking data from a Nextwindow-API compatible screen. This enables you to use many multitouch applications developed for optical tracking solutions on your Touchsmart PC.
Touchsmart TUIO requires Windows XP or Vista and a Nextwindow-compatible touchscreen with the necessary drivers installed.
You should turn off the touchscreen's mouse emulation in the "Pen Input" settings in the System Control Center before using the TUIO bridge. Otherwise, your touches will still be interpreted as mouse motions, which might interfere with the applications you might want to use the TUIO bridge with.
The Nextwindow screens on HP Touchsmart PCs can only track up to two simultaneous touches (this limitation might be gone in future hardware revisions).
Also, the exact position of two simultaneous touches on Nextwindow screens might not always be determined correctly, but the relative motion between the touches will always be tracked correctly (this limitation might also be gone in future hardware revisions.)
Release notes for official releases are available here.