HQ9+

HQ9+ is a joke language with four instructions:


 * H: Print "hello, world"
 * Q: Print the program's source code
 * 9: Print the lyrics to "99 Bottles of Beer"
 * +: Increment the accumulator

Although the language is not of serious interest by itself, it can be useful to implement HQ9+ in a new esoteric programming language, since doing so proves that all the tasks above, except the quine, are possible. HQ9+ was created in 2001 by Cliff L. Biffle.

External resources

 * HQ9+ as an embedded language in Haskell
 * Online HQ9+ interpreter in JavaScript
 * Online HQ9+ interpreter realized with PHP
 * HQ9+ interpreter in C by User:mmphosis
 * HQ9+ interpreter in Pascal by User:GrandKeyboard
 * hq9plus - HQ9P implementation for Parrot
 * hq9plus - HQ9P implementation for Parrot