OpenRA

OpenRA is an open source reimplementation of Command & Conquer: Red Alert, Dune 2000, and Command & Conquer: Tiberian Dawn written in C# using SDL which allows cross-platform programming for Windows, *BSD, Mac and Linux. At the first execution, it automatically downloads the original game files or installs some of them from the original game discs if such an option is chosen.

Features
The UI is modernized and has been tidied up, resembling that of newer Command & Conquer titles. For example, it is possible to queue build orders. A game lobby exists for Internet and network play. As the game features its own map editor, there are many custom maps available on |OpenRA Resource Center.

It also features fog of war and capturable civilian structures. To balance the overall strengths and weaknesses of factions, the tech trees and unit stats have been altered from the original game properties; for example, in the Red Alert 1 mod, the Allied artillery has increased firepower and a much longer range, the Soviets has the Mobile Flak unit borrowed from Red Alert 2 which can attack both ground and air targets, and the Ranger can now transport an infantry unit. Infantry cannot be run over as easily and will automatically try to evade being crushed by incoming heavy vehicles, making them more useful in the late game.

Certain visual elements have been updated too: planes and certain projectiles leave contrails in their wake, tanks and harvesters don't simply explode and disappear when killed instead breaking apart in pieces and leaving husks, which can be captured. The game UI also features usability improvements such as defense structures showing their weapon range radius when being placed and players can customize their player color instead of being limited to the original palleted color schemes.

Future developments
As of June 2014, the development team has been working on a Command & Conquer: Tiberian Sun reimplementation to the project. The official YouTube channel of OpenRA previewed the reimplementation of Tiberian Sun in July 2015. By February 2016, an implementation of Command & Conquer: Red Alert 2 was also announced and previewed. It is currently in development in a separate repository by the community.

Several mods, such as Crystallized Doom and Attacque Supérior, have switched from the original Westwood releases of Tiberian Sun or Yuri's Revenge to OpenRA.