Return of Zombie Ops is a zombie modification for Call of Duty 4, it features content from Black Ops Zombie mode aswell as from Modern Warfare 3 Survival mode and Ghosts Extinction mode. It's set slightly in the future with some weapons from Ghosts, Black Ops series and Modern Warfare series.
Final release of RoZo v0.5, no more big updates on this.
This is the final release of v0.5 so far, we'll keep on v0.6 from now on, support for this version will be kept up. Some small updates will follow when time goes by, due to new map features, we want to keep this version compatible to all maps that might come out.