INTERCAL

Description #

INTERCAL (short for Compiler Language With No Pronounceable Acronym) is a satirical and deliberately obtuse programming language designed to parody the complexities and idiosyncrasies of other languages. Its syntax is intentionally bizarre, using keywords like PLEASE, IGNORE, and COME FROM, with the goal of making programming as confusing as possible.

History #

INTERCAL was created in 1972 by Don Woods and James M. Lyon, two Princeton University students. It was a response to the perceived complexity and formality of languages like Fortran, COBOL, and assembly. INTERCAL remains one of the earliest and most influential esoteric programming languages, inspiring countless others.

Key points:

• Originally implemented on an IBM 360
• Re-released with C versions in the 1990s
• Considered a cultural artifact in programming humor
• Celebrated in hacker folklore and academic jokes

Hello World Code #

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

How to Run #

1. Install a C-INTERCAL compiler:
   https://catb.org/~esr/intercal/
2. Save code to a file, e.g., hello.i
3. Compile and run:

ick hello.i

Or try an online interpreter:

• https://tio.run/

Key Concepts #

• Uses PLEASE to increase politeness — insufficient politeness causes compile errors
• DO, COME FROM, IGNORE, FORGET are valid statements
• Rejects familiar constructs like loops and conditions
• Numbers are expressed using binary-encoded decimal
• Operates on registers and arrays
• Uses overcomplicated control flow for satire
• C-INTERCAL added modern features like multi-line strings
• Known for being intentionally unreadable
• Popular in esolang competitions
• Documents often read like parody literature

Try It Online #

🔗 TIO.run – INTERCAL
🔗 Esoteric Interpreters Archive

Fun Facts #

• The original creators described it as “not meant to be useful.”
• The COME FROM statement is a mockery of GOTO.
• The politeness threshold is real—programs crash without enough PLEASE.
• “IGNORE” literally ignores the variable forever.
• Known for triggering philosophical debates among language purists.

Resources #

• Official C-INTERCAL Homepage
• INTERCAL Wikipedia
• Esolang Wiki – INTERCAL