On a
Unix system, if you have a
crontab file, typing "crontab -l" will typically show you something like this:
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.4377 installed on Wed Sep 13 10:54:44 2000)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
# crontab
etc, etc
In this context, "vixie" refers to Paul Vixie, author of cron and other handy utilities. That whole Id mess has to do with the version control he used, and "vixie" specifically refers to the account he used to check in the code.
The Slashdot guys often refer to him as just "vixie"; I guess he's one of those single-name hackers like Linus, Spaf and Guido.