Chris Best says,
Since you guys seem to be collecting xxx references on the internet: The original physics preprint archive, the first internet system to distribute scientific papers, started in August 1991 under the name xxx.lanl.gov on a Sun computer in the corner of Paul Ginsparg's Los Alamos office. It's officially called arxiv.org now, but many people in physics still call in "Triple-X". Paul even uses skulls to interpret his X'es. Took me years to realize that this has a completely different meaning outside science :-)
Previously:
– More unexpected XXX: Amsterdam traffic pillars
– BB readers: XXX root beer, XXXX beer, Guber burgers
– Yet another '50s kitsch restaurant called "XXX"
