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

• [] [1]
• 0x29A [2]
• 23
• 4DL, a Befunge descendant

A

• Ale [3]
• ALPACA, a meta-language for programming arbitrary cellular automata
• ARCAL [4], a language for cellular automata
• Argh!, A Fungeoid with complex data storage.
• ASQ Product user led language
• Aura, a Brainfuck descendant

B

• B5 [5]
• BAK
• BANCStar [6]
• BDAMD
• Beatnik
• Befreak
• Befunge
• beta-Juliet [7]
• BFM [8], a Brainfuck variant with macros
• Blank
• BlooP
• BogusForth [9]
• Bon programming language
• Boolfuck [10]
• Boo-yah! [11]
• 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
• C-P-L [[12]], in which a non-comment is a syntax error (but on the plus side, all styles of comments are supported, and comments may be arbitrarily nested).

D

• Dis [13], a variant of Malbolge
• DOGO, a fictional joke language
• Doublefuck, an extended version of Brainfuck

E

• Emoticon [14]
• Enema programming language [15]
• ETA

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

• Gammaplex
• Gorby
• GOTO++
• GPLZ

H

• Haifu [16]
• Hanoi love [17], a Spaz derivative
• hBefunge [18], a superset of Befunge-93
• Homespring [19], an excessively high-level language, where the instructions are English sentences based around the metaphor of a mountainside river.
• HQ9+
• HQ9++
• Hunter [20], a language related to noit o’ mnain worb and RUBE

I

• iag [21]
• Illberon , a variant of Illgol
• Illgol [22]
• Illgola-2 , a variant of Illgol
• Illgol## , a variant of Illgol
• INTERCAL
• Iota

J

• Java2K, a probabilistic language
• Jot
• Justif & Recursion [23]

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 [24]
• Malbolge
• Maentwrog
• MDPN [25], 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 [26], a particle automaton
• nouse [27]
• NULL [28], 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 [29], Latinized Perl
• Piet, an art-based programming language
• PingPong [30]

Q

• Q-BAL [31], a queue-based language
• QUOTE, a Brainfuck-inspired language written to be a wrapper around Perl and C

R

• REDGREEN [32], an update of RUBE
• reMorse [33]
• RENE
• REVERSE [34]
• Romantic
• RUBE [35], not quite a cellular automaton

S

• Sally
• Sansism , a mixture of Befunge and Brainfuck
• SARTRE, a fictional joke language
• Shakespeare, programs appear to be Shakespearean plays
• Shelta [36], sometimes described as a minimal version of FALSE
• SIMPLE, a fictional joke language
• SLOBOL, a fictional joke language
• SMETANA
• SMITH, successor of SMETANA
• SMITH# , described as "the future of GOTO"
• Smurf , a stripped-down version of Muriel
• Snobol4
• SNUSP
• SON-OF-UNBABTIZED [37]
• SORTA
• Sorted! [38]
• Spaghetti
• Spiral [39]
• Spaz
• Spoon, a Brainfuck derivative
• Sqirrel - Peter [40]
• SQUISHY , a language based on semi-Thue grammars
• STOOPID

T

• Tamerlane [41]
• thETA , a threaded version of ETA
• THRAT
• Thue, successor of SQUISHY
• TMMLPTEALPAITAFNFAL
• Toadskin [42]
• trac
• TRANSCRIPT
• TRUE [43], a variant of FALSE
• TURKEY BOMB [44]
• TWDL[I]

U

• UNBABTIZED [45]
• Unlambda, a minimal functional language based on the s and k combinators
• URISC, a machine with only one instruction

V

• VALGOL, a fictional joke language
• var'aq [46], a Klingon programming language

W

• *W [47]
• Waduzitdo [48]
• WAFL
• Whenever, a language with no sense of urgency
• Whirl, two instructions to rotate two rings
• Whitespace, only spaces, tabs and newlines are considered syntax
• Wierd
• WorLD [49]

X

• XS [50], an XML-based language

Y

• Y , a FALSE-like language

Z

• ZT, a Befunge-like language

See also

• Hello world program in esoteric languages
• List of programming languages
• Turing tarpit

External links

• New Cat's Eye Technologies Site
• Cat's Eye Technologies: Esoteric topics in computer programming (archived version from the Wayback Machine)
• Ryan Kusnery's list of weird programming languages
• The retrocomputing museum
• Lesser-Known Programming Languages
• Encyclopedia of esoteric programming
• The Turing tarpit
• The random programming languages list
• C2 WikiWeb