Poclbm (PyOpenCL bitcoin miner) is a python GPU bitcoin miner that uses the OpenCL framework to quickly perform the hashing computations. Works with AMD - 4xxx and up, Nvidia - 8xxx and up, video cards.
From the Known Settings part of the introductory post.
Windows 7 64, Stream 2.2, AMD 5[7-8]70
Use '-v -w 128' with '-f 30' on 5770 (160 MHash), '-f 5' on 5870 (318 MHash)
Open source, but no mention of which open source license was found.