The Matrix Weapons mutator for Unreal Tournament Game of The Year Edition was effectively a set of Counterstrike weapons converted for use in UT GOTY, with an added feature of slow-motion, like in The Matrix. Turning on bullet time would slow everything down, giving the player superhuman speed and reflexes, with super-cool weapons.
It was a fun mod to play with.
Unzip both files from the zip file and copy them into your Unreal system directory. (i.e. C:\UnrealTournament\System) then fire up a text editor and open up your UnrealTournament.ini file, which is in the same directory. Find the [Engine.GameEngine] section and scroll down to the end of the ServerPackages entries. Add an entry like so:
Save and close the file. After that, you should be good to start UT and add the Smack’s Ultimate Gun Pack mutator to any match you like. Remember to bind a key for the slomo toggle!