Open Source alternative to Mixamo

Open Source alternative to Mixamo

I'm sure we can get this done.
Basically I want humanoid animations that can be used for 3D games.
At the moment most of us are relying on adobe for animations and that isn't the best situation in my opinion.
What would be even better is if we can take already existing animations in other open source games and rework them into a standardized rig.

What I'm most looking for are animations that can be used with the Unreal Mannequin. Can someone help?
game-anims.github.io