In an effort to boost Command & Conquer 4 hype, EA is offering older instalments in the series for free.
Tiberian Sun (1999) and expansion Firestorm have been added to a freeware list that already features Tiberian Dawn and Red Alert.
You can't download them from EA anymore, but a helpful chap called Tom Bennet has collated links to community-maintained installers and you should be able to download them there.
Tiberian Sun - a prequel to C&C3: Tiberium Wars - played out the events of a second war between Nod and GDI forces and introduced a new game engine, rail-gun shooting AT-AT things and plenty of other futuristic-style units.
Command & Conquer 4: Tiberian Twilight will be released for PC only on 19th March. Check out our Command & Conquer 4 preview to find out more.