Wyrmsun - Free open sourced RTS, that's very much like the 90's Warcraft

Game Type : RTS
Developer : Andrettin
Developer Description : Wyrmsun is an open-source RTS game which features elements of mythology, history and fiction. In the Wyrmsun universe a myriad of inhabited planets exist. Humans dwell on Earth, while dwarves inhabit Nidavellir and elves nourish the world of Alfheim. These peoples struggle to carve a place for themselves with their tools of stone, bronze and iron. And perhaps one day they will meet one another, beyond the stars...

Screenshots :

Features:

• Retro-style graphics
• 2 playable civilizations, and a number of non-playable ones
• 20 quests to play, earning technology points which can be used to obtain new units, buildings and technologies
• 38 units, 30 buildings and 18 technologies
• Units that can earn experience, being able to upgrade to new unit types or acquire new abilities upon level-up
• Persistent heroes, who carry over their level and abilities throughout scenarios
• Personal names and traits for units
• Cave, Conifer Forest, Dungeon, Fairlimbed Forest and Swamp tilesets
• 35 maps of real and fictional locations to choose from, as well as random maps
• Living environment, with fauna reproduction and predation
• Very moddable game, with mod-loading capability built in
• Grand strategy mode, where production is resolved on the strategic (world map) level, while battles are resolved on the tactical level
• In-game encyclopedia, allowing players to learn more about the units, buildings and other elements of the game, as well as their historical and mythological sources of inspiration

Systems : PC, Linux
Links : 1) Source 2) Indiedb 3) Steam (Not free)