wuarchive
Washington University in St. Louis's FTP archive, one of the biggest places on the early-90s net to fetch software from.
Anyone with anonymous FTP could pull mirrors of nearly everything from wuarchive.wustl.edu: Simtel's DOS collection, Mac and Amiga archives, X11, GNU tools, RFCs and image collections. By the standards of the day it was enormous, at tens of gigabytes, and so heavily loaded that logins were routinely refused with a polite note that the maximum number of anonymous users had been reached.
The traffic forced the creation of a dedicated FTP server. It shipped with Unix systems as wu-ftpd, which made a university archive in Missouri the origin of one of the internet's most widespread — and most exploited — pieces of server software. Archie was the usual way of discovering that the file you wanted lived here.