Wolf Coop is a vanilla Coop Game mode for Unreal Gold that adds a lot of Quality of Life settings for Gameplay, a reworked HUD & Scoreboard, and a better Admin Login system. It also comes with settings for Lives and Checkpoints, Item Respawning, End Voting and more. Almost everything about the mod can be changed in the settings, giving server hosts a lot of freedom in the kind of experience they want to offer. (While mainly a coop mod, it is fully functional for SinglePlayer as well!)
myeh
Works great in coop the way it should. You can tweak the settings but the game actually remembers stuff like player inventory and the level they finished last time.
Weapons can be set to respawn or made unique per player so you can only pick them up once if you want that SP experience.
The way the game was meant to be played in coop!