*BF2 "Revive" is no different than a regular BF2 "Vanilla" version!*
Ok so this may be a bit confusing, but put simply Battlefield 2 Revive Project is a team of dedicated guys who have made Battlefield 2 from the ground-up, and have released it for free.
And in October they will be releasing Battlefield 2142 Revive. Feels like a good freebie to me.