Outcast was published for Windows in 1999 by Infogrames and, though not a wild success, it became an innovative and instant classic. Its unique voxel graphics, the huge detailed (open) world, a wild plot and the intriguing gameplay assured Outcast's seat in the late '90s pantheon of PC games. Oh, and here's a making of of Outcast to further enlighten you.
To own a complete boxed copy of the thing, you can bid on this Outcast (PC) auction. It's complete with manual and 2 CDs, and the seller ships to most places around the world.