Prodod is a third party Day of Defeat: Source mod that builds on the foundation set down by DOD:S. Various key values from DOD:S have been changed to better suit the competitive community, as well as correct certain things in the game that Valve has consistently stated they will not ever address.
This is a self installer for the game. Just run the installer and click on desktop icon to play the game. Your game will always stay current to the files we upload. You and the people you are playing with will always have the same version of the game. Sound familiar?