https://github.com/spec-framework/spec/commit/07ea83ca50523b4a912e363ff2f3974c69314b7f#commitcomment-7540588
I think the license might need further improvements. I've taken a look at the commit history, and it looks to me like there is a licensing problem there. I am no lawyer, so don't know what the exact consequences of that are. The (MIT licensed) Pharo code was copied to the repository without including the copyright notice, as is required by the MIT license. For new contributions, you now have the license agreements, and with git it is perfectly clear what is new, and under the new license, and what is old, and can therefore also be used under the old license. And AFAIK MIT license is compatible with GPL. I have no clue as to the license status of changes between the copying and the relicensing. Of course copyright holding contributors can decide to relicense. The contributors to the Spec-* packages in the Pharo/Pharo30 repo seem to be: AlainPlantec AndreiChis BenComan BenjaminVanRyseghem BernardoContreras CamilloBruni CamilleTeruel ChristopheDemarey ClementBera DamienCassou ErwanDouaille EstebanLorenzano GabrielOmarCotelli GuillermoPolito HernanMoralesDurand IgorStasenko LeoGassman MarcusDenker MartinDias NicolaiHess PabloHerrero PavelKrivanek PhilippeBack RobertoMinelli SeanDeNigris SebastianTleye StephaneDucasse SvenVanCaekenberghe TorstenBergmann TudorGirba YuriyTymchuk Stephan
