Foobar - History and Etymology

History and Etymology

The origins of the terms are not known with certainty, and several anecdotal theories have been advanced to identify them. The first known use of the terms in print appear in a 1965 edition of MIT's "Tech Engineering News." Foobar may have derived from the military acronym FUBAR and gained popularity because it is pronounced the same.

The etymology of foo is explored in the Internet Engineering Task Force (IETF) RFC 3092, which notes usage of foo in 1930s cartoons including The Daffy Doc (with Daffy Duck) and comic strips, especially Smokey Stover and Pogo. From there, the term migrated into military slang, where it merged with FUBAR. The term foo fighter was used by Allied aircraft pilots in World War II to describe various UFOs or mysterious aerial phenomena.

The use of foo in hacker and eventually in programming context may have begun in MIT's Tech Model Railroad Club (TMRC). In the complex model system, there were scram switches located at numerous places around the room that could be thrown if something undesirable was about to occur, such as a train going full-bore at an obstruction. Another feature of the system was a digital clock on the dispatch board. When someone hit a scram switch the clock stopped and the display was replaced with the word "FOO"; at TMRC the scram switches are therefore called "Foo switches". Because of this, an entry in the 1959 Dictionary of the TMRC Language went something like this: "FOO: The first syllable of the misquoted sacred chant phrase 'foo mane padme hum.' Our first obligation is to keep the foo counters turning."

One book describing the MIT train room describes two buttons by the door: labelled foo and bar. These were general purpose buttons and were often re-purposed for whatever fun idea the MIT hackers had at the time, hence the adoption of foo and bar as general purpose variable names.

The term foobar was propagated through computer science circles in the 1960s and early 1970s by system manuals from Digital Equipment Corporation.

Foobar was used as a variable name in the Fortran code of Colossal Cave Adventure (1977 Crowther and Woods version). The variable FOOBAR was used to contain the player's progress in saying the magic phrase "Fee Fie Foe Foo".