Esoteric Programming Languages: Malbolge, INTERCAL, Brainfuck, COW, Whitespace, and Wenyan

This article introduces several esoteric programming languages—languages intentionally designed to be obscure or difficult—and provides brief descriptions and “Hello, world” code samples for each.

Malbolge (designed by Ben Olmstead in 1998) uses a ternary system, self‑modifying code, and random execution. It is considered one of the hardest languages to write. Example output program:

(=<`#9]~6ZY32Vx/4Rs+0No-&Jk)"Fh}|Bcy?`=*z]Kw%oG4UUS0/@-ejc(:'8dc

INTERCAL (1972, by Don Woods and James Lyon) satirizes conventional languages. Its “Hello, world” program consists of a series of obscure statements:

DO ,1 <- #13
PLEASE DO ,1 SUB #1 <- #238
DO ,1 SUB #2 <- #108
DO ,1 SUB #3 <- #112
DO ,1 SUB #4 <- #0
DO ,1 SUB #5 <- #64
DO ,1 SUB #6 <- #194
DO ,1 SUB #7 <- #48
PLEASE DO ,1 SUB #8 <- #22
DO ,1 SUB #9 <- #248
DO ,1 SUB #10 <- #168
DO ,1 SUB #11 <- #24
DO ,1 SUB #12 <- #16
DO ,1 SUB #13 <- #162
PLEASE READOUT ,1
PLEASE GIVE UP

Brainfuck (1993, by Urban Müller) is a minimalist Turing‑complete language with only eight commands. Its “Hello, world” program:

++++++++++[>+++++++>++++++++++>+++<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.

COW (2003, by Sean Heber) uses only the word “moo” (and variations) as instructions. Sample program:

MoO MoO MoO MoO MoO MoO MoO MOO moO MoO MoO MoO MoO MoO moO MoO MoO MoO MoO moO MoO MoO MoO MoO moO MoO MoO MoO MoO MoO MoO MoO
 MoO MoO moO MoO MoO MoO mOo mOo mOo mOo mOo MOo moo moO moO moO moO Moo moO MOO mOo MoO moO MOo moo mOo MOo MOo MOo Moo MoO MoO
 MoO MoO MoO MoO Moo Moo MoO MoO MoO Moo MMM mOo mOo mOo MoO MoO MoO MoO Moo moO Moo MOO moO moO MOo mOo mOo MOo moo moO moO MoO
 MoO MoO MoO MoO MoO MoO MoO Moo MMM MMM Moo MoO MoO MoO Moo MMM MOo MOo MOo Moo MOo MOo MOo MOo MOo MOo MOo MOo Moo mOo MoO Moo

Whitespace (2002, by Edwin Brady and Chris Morris) encodes instructions using only spaces, tabs and linefeeds. A fragment of a “Hello, world” program (S = space, T = tab, L = linefeed):

S S S T  S S T  S S S L
T  L
S S S S S T  T  S S T  S T  L
T  L
S S S S S T  T  S T  T  S S L
T  L
S S S S S T  T  S T  T  S S L
T  L
S S S S S T  T  S T  T  T  T  L
T  L
S S S S S T  S T  T  S S L
T  L
S S S S S T  S S S S S L
T  L
S S S S S T  S T  S T  T  T  L
T  L
S S S S S T  T  S T  T  T  T  L
T  L
S S S S S T  T  T  S S T  S L
T  L
S S S S S T  T  S T  T  S S L
T  L
S S S S S T  T  S S T  S S L
T  L
S S S S S T  S S S S T  L
T  L
S S L
L
L

Wenyan (wenyan-lang) follows Classical Chinese syntax. Its “Hello, world” program:

吾有一數。曰三。名之曰「甲」。
為是「甲」遍。
  吾有一言。曰「「問天地好在。」」。書之。
云云。