Autumn Aurora 2 it's modification made by small group from Poland which brings the autumnal atmosphere to the Zone and totally overhauls the graphics, audio and gameplay of S.T.A.L.K.E.R. Shadow of Chernobyl.
Frequently asked questions about Autumn Aurora 2 regarding compatibility, tweaks etc. UPDATED for 2.1 on 06.12.14
A short list of Autumn Aurora 2 graphics, sound and gameplay features.