The ogsm.zip file you have requested: Clear Sky / Mods / Singleplayer / OGSM CS BUILD 3 - 64.69mb is not available. Perhaps try browsing all files for the game S.T.A.L.K.E.R.: Clear Sky and upload any files you want to share or are missing. This is the only information we could locate:
I found this mod on a Russian site. Was able to get through the install process, and was able to play it. Over all it was amazing. The mod adds brand new features. Improved AI, HD Textuers, New Items ECT. This is the newest version of the mod, with it includes patch 3. This is only a build but it is pretty cool. Expect Glitches.