After EA already released the source code for the Red Alert/Tiberian Sun DLLs in the Remastered Collection a few years ago, some more repositories follow:
They also included updated modding tooling in another repository:
Additionally, all these games in the Ultimate Collection on Steam now have workshop support enabled, so people can actually build things and publish them for all those games.
As an extra, they also uploaded a video with archive footage from Renegade and Generals, showcasing tech demos and prototypes:
You can read the full announcement from EA on Steam:
