The project is a HD texture mod for the first part of the game series Thief: The Dark Project / Thief Gold.
Thief Gold HD Mosaic Wallpaper. It contains thousands of gaming screenshots from Thief Gold. The total resolution is 4671 x 3542 pixels!
And here you can find the new versions of the Thief Gold HD Mosaic Poster. They contains over 30.000 pictures! The total resolution is 11680 x 8685 pixels. So it's perfect for a big poster. You can download it on flickr.