A set of small, piecemeal mods for various aspects of S.T.A.L.K.E.R.: Clear Sky. Stash Auto-Filler, modifiable "Trophy" AK-47/2, cut content restoration (including cut monsters/mutants) and others, all available as individual packages for each change.
Holy crap, it's a Burer! While they aren't as mind-blowing powerful in Clear Sky as they are in Call of Pripyat they still provide a fairly significant threat. You'd be wise to take them down as quickly as possible.