Poxelcoll (Polygon/pixel-perfect collision detection library) is a FOSS library designed to support easy, flexible and efficient pixel-perfect collision detection, including simple transformations such as scaling and rotation.
Poxelcoll is as of 2012-05-12 at version 0.1, should be ready for use, and is available in Scala 2.9 and C++11.
See the manual and the APIs for each implementation.
The license for the library is GPL v3. See the LICENSING document for more information.