AMD Open-Sources Compressonator Project
AMD Compressonator is also known formerly as just "AMD Compress" and was a closed-source compression tool available to developers. Compressonator is about compressing textures and creating mip-map levels. The tool is designed around DXTn/S3TC.
More details on Compressonator going open-source were announced today via GPUOpen.com. The code is hosted on GitHub. The project up to now has been focused upon Microsoft Windows but with now being open-source we will hopefully see it ported to Linux for helping game developers/porters.