Looking for good freeware strategy games

Age of Empires online is for free, if you're into that kinda thing

Frontline Tactics, Airmech, Age of Empires Online. They are all on steam.

0 A.D. is free Indie game http://play0ad.com/

FreeCiv

Warzone 2100

Shattered Galaxy and Mankind.

give these two games a try

Spring RTS - http://springrts.com/ has alot of different games of RTS on its engine

MegaGlest - http://megaglest.org/

Knights and Merchants Remake
OpenRa
OpenDune
Spring RTS Engine
Unknown Horizons
Warzone2100
Zod Engine
Tiberian Sun

You can try Starcraft II. But you are only able to play with Terrans

Total Annihilation: Spring

Check here: http://www.mmobomb.com/games/mmorts

Assault Squad Online (http://assault-squad.com/) rather reminds me of a WWII-themed version of the Advance Wars series. It's online, browser-based, and asynchronous.

Steel Panthers, though older, is something you might want to look into, but because of how it became free it can be a bit of a hassle to track down exactly which version.

Here is a cute strategy game I like. It is about a war between pigs and rabbits. S.W.I.N.E.

nevermind, I see now the mentioned Battle for Westnoth lol

If you like the X-Com/UFO games you could check out UFO: Alien Invasion.

I haven't tried it yet myself, but it seems like it might be pretty good. There is multiplayer support as well.

"UFO:AI supports multiplayer in different scenarios. You can play 1on1, 2on2 and so on. Even cooperative games are possible. But you have to be aware, that not all maps are coop playable - or maybe only with a specific team. Some smaller maps will have the spawn points of the aliens near the spawnpoints of multiplayer team 1 or 2 - so no real coop gameplay comes up here."

Thanks everyone! We will try some of this today.