This is a shirt printed in 1985. It embodies the unix community's outlook; juvenile, sloppy, and happy-go-lucky. Look at the daemons messing, with forks and pipes and null buckets. The leaking pipes and sprawling architecture. Infighting and inanity. Look at the left two, one whacks off another whacko, while the right two are sloths and do-nothingers.
Note these terms are puns. They have technical meanings in
unix. Daemon is a “background process” or a program that runs in the
background. Fork is spawning a new a process by copying. The concept of fork
is a unix idiosyncrasy, grew out of bad habit and brainlessness. Pipe
is in a sense a syntax for postfix notation (which can be sequenced),
or more commonly thought as of a way to transmit data from one program
〔☛ Unix Pipe as Functional Language〕
Null Buckets refers to the null device
can be thought of as a trash bin.
The above photo is from the site http://www.mckusick.com/beastie/shirts/usenix.html (accessed on 2002-05), which gives a history of the shirt and art design. Here's a quote:
The shirt shown in the first picture shows the original Phil Foglio art that was the basis for the shirt shown in the second picture, commissioned for the tenth anniversary of the Usenix organization. Each attendee at the June 1985 summer conference held in Portland, Oregon received one of these shirts.
See also Wikipedia: BSD Daemon.