http://www.ccil.org/retro/retromuseum.html
The Retrocomputing Museum is dedicated to programs that induce sensations
that hover somewhere between nostalgia and nausea -- the freaks, jokes, and
fossils of computing history. Our exhibits include many languages, some
machine emulators, and a few games.
[My favorite is...]
kvikkalkul
A very odd little language, probably a joke but alleged to have been used
for embedded-systems control on Swedish nuclear submarines in the 1950s.
Notable for its probabilistic-jump instruction.
[And of course...]
BASIC
BASIC lives -- unfortunately. This version implements most of the
notoriously bad ANSI X3.113-1987 standard for Full Basic. As the Computer
Contradictionary says, "Shit with icing".