INTERCAL is an esoteric programming language created by Don Woods and James M. Lyon, both Princeton University students, in 1972.
The full name of the language is the Compiler Language With No Pronounceable Acronym, but it is abbreviated INTERCAL. It was created as a parody of the various programming languages of the time and intended to be completely different from all other programming languages. Nevertheless, it is Turing-complete. Given sufficient memory, INTERCAL can solve any problem that a Universal Turing Machine can solve, although what a program written in C can solve in less than half a second might take more than seventeen hours in INTERCAL, if everything else is equal.
As an example of the difficulty in writing code for INTERCAL, the language expects the programmer to use PLEASE as a modifier. If PLEASE does not appear often enough in the code, the program is considered insufficiently polite, according to the error message. On the other hand, if PLEASE is used too often, the program could be rejected for being excessively polite. Although this feature existed in the original INTERCAL compiler, it was not documented.
Anything the INTERCAL compiler doesn't understand is just skipped, making bug detection difficult. On the other hand, program comments can be made anywhere. The programmer simply inserts non-compilable text anywhere in the program, being careful not to accidentally include valid code in the middle of the comment.
Currently, there are two maintained versions of INTERCAL. C-INTERCAL is maintained by Eric S. Raymond, and CLC-INTERCAL is maintained by Claudio Calvelli.
Esoteric programming languages are not generally intended to be useful but are created as challenges by programmers or in jest.
Topics related to the INTERCAL programming language, or one of its versions, dialects, or implementations, are the focus of topics in this category. Any user groups, tools, guides, or manuals are also appropriate here.
Recommended Resources
Available as a free download through the GNU General Public License version 2.0, a compiler for the original esoteric INTERCAL programming language is made available in a package that includes the compiler, a debugger, and sample code. Other documentation includes known bugs, a history of the language, development news, and other documentation. This package is an implementation of the language INTERCAL, designed by Don Woods and James Lyon.
https://gitlab.com/esr/intercal/
Karsten Sperling offers an overview of J-INTERCAL, a Java implementation of the INTERCAL programming language designed by Don Woods and James Lyon. The J-INTERCAL Project attempts to deliver the full power of INTERCAL on every Java-enabled platform, allowing for INTERCAL on handhelds and cellphones. The latest version of the language may be downloaded from the site, including the source code, and documentation and links to related sites are included.
http://spiff.de/jintercal.html
Characterized as the performance art of programming, the site is maintained by Brian Raiter, and focused on the programming language known as INTERCAL. Featured are links to basic resources for the language, other INTERCAL implementations, several programs created in INTERCAL by Brian Raiter, and other information, programs, and resources related to the esoteric language, including an archive of the 1992 Computer Shopper article on the language.
http://www.muppetlabs.com/~breadbox/intercal/
Described as the ultimate challenge for programmers, INTERCAL was designed to be Turing-complete but as unlike any other programming language as possible. Originating in the early 1970s, the language was revived in 1990 by the C-INTERCAL compiler. Featured here are the README, NEWS, and BUGS distribution files, the Revamped INTERCAL Manual, and the Revised INTERCAL Manual, along with other resources, such as essays and a weblog.
http://www.catb.org/~esr/intercal/
