Yesterday, the Winamp source code, build tools, and associated libraries for the Windows app were published on GitHub, allowing anyone to provide bug fixes and new features to the iconic media player.
However, its license prohibits the distribution of modified software created through the release of this source code.
the GPL does not require upstreaming. it would allow for anyone to redistribute Winamp with whatever modifications they like, provided they publish their source code under the GPL. the license Winamp is using is not even an open-source license since it explicitly forbids public redistribution. dumb move, they should have just used MIT or GPL and retained rights to the logo or something