Specifically look for the names like Navy Seals and True Combat. True Combat just had its 1.0b release recently and it's the most mac friendly q3 mod to install that I've seen to date(not that q3 mods are hard to install in the first place but... ). Based on my limited playtime of True Combat before I uninstalled it (realism still isn't my thing) I can tell you that it takes the level of realism that you find in Urban Terror to a new level. You have to use the iron sights of the gun to aim at your opponents, to pick up guns and other stuff you must crouch over them, walls and doors apparently can be blown open, etc. That's just to give you an idea of what it's like.