I think that Joel is right and that it's just loaded from archive.org. The guy behind the site just seemed to pick stuff that was iconic for that era. Donde Quake 2
also has a lot of stuff archived if you're looking to take a trip down memory lane, although most of it is obviously focused on Quake 2. They have a snapshot of Redwood's page
on Stomped, which actually looks like it was taken in 97.