list of esoteric programming languages

The following is a list of esoteric programming languages (programming languages designed as a proof of concept, to test the boundaries of computer language definition, or as jokes, and not with the intention of being adopted for real-world programming).

0-9

[] http://p-nand-q.com/humor/programming_languages/brackets.html
0x29A http://xyzzy.bravehost.com/0x29A.html
23
4DL, a Befunge descendant

A

Ale http://web.archive.org/web/20030629204820/crunchybear.com/ale/
ALPACA, a meta-language for programming arbitrary cellular automata
ARCAL http://www.collidoscope.com/ca/arca.html, a language for cellular automata
Argh!, A Fungeoid with complex data storage.
ASQ Product user led language
Aura, a Brainfuck descendant

B

B5 http://www.sange.fi/~atehwa/b5/defn.en.txt
BAK
BANCStar http://www.geocities.com/ResearchTriangle/Station/2266/tarpit/bancstar.html
BDAMD
Beatnik
Befreak
Befunge
beta-Juliet http://catseye.mine.nu:8080/projects/b_juliet/
BFM http://www.pimpworks.org/brainfuck/utils/eso_bfm/, a Brainfuck variant with macros
Blank
BlooP
BogusForth http://it.geocities.com/tonibin/bf/bfwhatis.html
Bon programming language
Boo-yah! http://esoteric.sange.fi/archive/2002-q1-1
Borg
Brainfuck, designed to have the smallest compiler ever
Brainfork, a multi-threaded brainfuck variant
Bub, a Brainfuck variant
Bubble
Bullfrog

C

C-, a fictional joke language
Chef
Choon
Condit
COW

D

Dis http://web.archive.org/web/20031209180058/http%3A//www.mines.edu/students/b/bolmstea/malbolge/index.html, a variant of Malbolge
DOGO, a fictional joke language
Doublefuck, an extended version of Brainfuck

E

F

FALSE
Fuckfuck (also known as F*ckF*ck, FeckFeck and FF)
FIFTH
FiPL Fish Programming language (half-joke, a parody on programming language paradigms)
Flatline, a Brainfuck derivative
FlooP
Fromage

G

H

Haifu http://www.dangermouse.net/esoteric/haifu.html
Hanoi love http://lilly.csoft.net/~jeffryj/compilers/hl/hl.html, a Spaz derivative
hBefunge http://www.bumba.net/~hmaon/hbef/, a superset of Befunge-93
Homespring http://www.rpi.edu/~bindej/hs.html, an excessively high-level language, where the instructions are English sentences based around the metaphor of a mountainside river.
HQ9+
HQ9++
Hunter http://catseye.mine.nu:8080/projects/hunter/, a language related to noit o’ mnain worb and RUBE

I

iag http://sange.fi/~atehwa/small-esoteric/
Illberon, a variant of Illgol
Illgol http://web.archive.org/web/20020617125506/www.catseye.mb.ca/esoteric/illgol/
Illgola-2, a variant of Illgol
Illgol##, a variant of Illgol
INTERCAL
Iota

J

Java2K, a probabilistic language
Jot
Justif & Recursion http://p-nand-q.com/humor/programming_languages/justif.html

K

Kipple, a minimalistic programming language where all data manipulation is done with stacks of integers
Kvikkalkul

L

L
l33t, inspired by Brainfuck and Beatnik, source code is entered as 'l33t 5p34k'
Lambda programming language, lambda calculus + neumann = self-modifying code
LAIDBACK, a fictional joke language
Lazy K
LITHP, a fictional joke language
L00P, a Brainfuck-style language

M

Magenta http://www.geocities.com/ResearchTriangle/Station/2266/tarpit/magenta.html
Malbolge
Maentwrog
MDPN http://web.archive.org/web/20020617125631/www.catseye.mb.ca/esoteric/mdpn/index.html, a meta-language extending the EBNF
MISC, an alternative to CISC and RISC
MUMON, a language with a 14-byte bootstrap
Muriel, a quine-based language

N

Nil programming language, a nihilistic programming language
noit o' mnain worb http://catseye.mine.nu:8080/projects/worb/, a particle automaton
nouse http://www.geocities.com/qpliu/nouse/
NULL http://xyzzy.bravehost.com/NULL.html, zero-dimensional language
Numberix, a language that has been compared to Befunge machine code
Nietzsche, an hexadecimal language

O

Obfuna, single character instructions for unary operations
ODDBALL
OISC, one instruction set computer
Ook, a brainfuck-style language
OOPS
Oroogu, a descendant of Q-BAL
Orthagonal, a two-dimensional stack-based language
OrthINTERCAL, a combination of Orthogonal and INTERCAL
Orthogonal, successor of Orthagonal

P

Pandora
PATH, derived from Brainfuck
pax
Perligata http://www.csse.monash.edu.au/~damian/papers/HTML/Perligata.html, Latinized Perl
Piet, an art-based programming language
PingPong http://www.inz.info/pingpong/

Q

Q-BAL http://homepage.eircom.net/~kmgaughan/esolang/q-bal/, a queue-based language
QUOTE, a Brainfuck-inspired language written to be a wrapper around Perl and C