BrainFuck
Brainfuck is an amusing and minimalistic programming language which doesn't serve any real purpose except being a funny joke, challenging programmers and testing the boundaries of computer language design.
Warning! Brainfuck isn't suitable for practical use when programming!
This is a piece of source code like Ed in Brainfuck language:
+[[,][-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.[-]+++++++++++++.---.+]
The following was offered from Andrea Bolognani, with this comment:
The above version reads from standard input until it encounters a EOF character, and then starts printing
?
in an infinite loop. I've written a drop-in replacement…as an added bonus, this version uses only 69 instructions, which is 30 less than the one above.
++[>+++++[>++++++<-]<-]++[>+++++<-]>>+++<<+[[,----------]>>.<.<+]
More information about Brainfuck language: http://en.wikipedia.org/wiki/Brainfuck.
Other humor in the GNU Humor Collection.
Disclaimer
The joke on this page was obtained from the FSF's email archives of the GNU Project.
The Free Software Foundation claims no copyright on this joke.
The code from Andrea Bolognani is licensed under the terms of the GNU GPL, version 2 or later.