"What do you mean it doesn't exist clientside?"
YARM: where player's Lean, Prone, Mantle, Dash, Crouch Jump, 'Parkour' and slide around all with generic realistic weapons!
My Generic Mods for UT2K4:
Yet Another Real-life Mod: Realistic weapons, unoriginal gameplay, w/ cheap CODMW knockoff mutator 
TD Vehicles: HUMV, MI4Hound, Motorcycle, IFAV Jeep, UH-60, MH-53 & AH-6 Helicopters, Abrams Tank