Here you will find the freely downloadable Motion2D software including the library and application examples provided under the Q Public License (QPL) restricted to non-commercial developments. This specifies that you may freely use Motion2D for development of open source/non-proprietary software. The Motion2D software is provided with no support and no warranty. See the Trolltech web site for more details about the QPL license.
The Motion2D archive is available in tar gzipped format. The archive contains the complete source code of the software, some examples and the online reference documentation in html. It compiles on some Unix and Windows platforms. The platform notes give the list of the supported platforms.