OpenRA is a game engine used to recreate the games: Red Alert, Tiberian Dawn, and Dune. It's 100% free to download and completely open source; meaning that you can create total conversion mods and games that can run independently of the main three titles.

Released in 1996 by Westwood Studios, Red Alert was the second entry in the hugely influential Command & Conquer series. It goes without saying, your dad played this game. The gameplay is your standard RTS affair, build a base, build an army, and wipe your competition off the map. Some of the cool things that differentiates OpenRA from the original game, are a host of balance changes, updated user interface, and new features. It's also as easy as ever to play with friends, just download and you're ready to play online.

With the game being a bit older the graphics aren't the most stunning in the world; but they're still pretty enough to convey the different types of units and display awesome firefights. The soundtrack is also killer, featuring 20 songs that get your blood pumping and puts you into the mind of a strategic commander.

Head on over to openra.net if you want to give it a try, and remember: Beware the nuke trucks....