Project reality is one of the gratest total conversion mods Battlefield 2 ever had, and development hasn't stopped. At the end of last month they released update 1.3 which trurned the mod in to a standalone game without requiering BF2 or its key at all. I have had my best squad based gaming experiences in this mod and would recommend for anyone into that kind of game style.
also has larger maps, more players(100 player servers), and has voip built in, unlike bf3/4