OpenHV is a completely free Open Source real-time strategy remake using the pixel art from the unrelease early-90s game Hard Vacuum. Based on the OpenRA engine.

Check out https://www.openhv.net/

OpenRA is an open source project to recreate the gameplay and atmosphere of classic real-time strategy games like the Command & Conquer series.

To download and play OpenRA for free go to https://openra.net

Join the OpenRA community on Discord: https://discord.openra.net/

Red Alert is the most played mod for the OpenRA engine and has an active scene of competitive players.

Join the competitive community on Discord: https://discord.gg/JyHZFbw

Learn how to play OpenRA like a pro in the OpenRA Academy Discord: https://discord.gg/C2CadJT

Check out competitive player track records on the competitive 1v1 Ladder: https://oraladder.net

Gaming on Linux

I'm playing OpenRA exclusively on Linux-based operating systems, currently Manjaro KDE edition.

Want to play?

OpenRA games have a steep learning curve in online multiplayer games, especially regarding 1v1 games. Make sure to check out some videos of how the advanced players approach the game. Even better: join the community on the OpenRA Academy Discord server, study the abundant learning material, connect and learn with other players!

Credits

Music by Frank Klepacki, original Tiberian Dawn and Red Alert soundtracks. Check out his work at https://www.frankklepacki.com/

TLDR: https://oraladder.net has all the pointers to competitive OpenRA :)