Ah, Mac OS X DP 3. Mac OS X DP3 was the third "Developer Preview" release of Mac OS X. Mac OS X DP3 was the first developer release to include the Aqua user interface introduced at MacWorld Expo 2000 in San Francisco.
Here are some links about Mac OS X DP 3, some include screenshots
http://arstechnica.com/reviews/1q00/macos-...os-x-gui-1.html
http://arstechnica.com/reviews/1q00/macos-...os-x-dp3-1.html
http://www.guidebookgallery.org/screenshots/macosxdp3
http://www.macuarium.com/macuarium/actual/...xdp3/index.html
http://tweakers.net/nieuws/9195/maxos-x-de...creenshots.html
http://www.stone.com/The_Cocoa_Files/Arise_Aqua_.html
http://apple.slashdot.org/article.pl?sid=00/02/22/1138218
http://www.macopz.com/rumors/DP3/
http://forums.macnn.com/84/mac-os-x-archiv...p3-screenshots/
Macworld San Francisco 2000-The Mac OS X Introduction. Introduction of Aqua
http://youtube.com/watch?v=Ko4V3G4NqII&feature=related (part 1)
http://youtube.com/watch?v=6-fkYFV7rOY&feature=related (part 2)
http://youtube.com/watch?v=2GkoAa5718Y&feature=related (part 3)
Waybacked versions of the original Mac OS X page, more early screenshots from DP3
http://web.archive.org/web/20000510030206/...osx/inside.html
http://web.archive.org/web/20000706210544/...osx/inside.html
http://web.archive.org/web/20000302232403/...x/graphics.html
http://web.archive.org/web/20010213233921/...x/graphics.html
http://web.archive.org/web/20000302003553/...acosx/aqua.html
http://web.archive.org/web/20010331074725/...acosx/aqua.html
http://web.archive.org/web/20000510005741/...osx/finder.html
http://web.archive.org/web/20000304002022/...sx/theater.html