Full discussion here
A bit of a non-standard post as I don’t think you can actually play them for free yet (I can’t see any binaries available and there’s a disclaimer that you need to already own the games, presumably for assets/art), but a pleasant surprise and hopefully something to keep an eye on!
Yeah, the disclaimer means the source code is 100% free, which will enable community patches and mods, but the art, music, etc is all still under copyright and not GPL or any other open licenses. That said, the freeware versions EA released some time ago are available on Cncnet. Don’t click the big download and play free, that button is the multilayer only, click the one under it and pick full game. You can also select other games available on the sidebar.