This category is for languages deliberately designed to be often unusable, unimplementable, or both. The stress is on "deliberately". A language that is unsuitable for actual programming not by intention but merely (1) due to its inventor's ineptitude, or (2) due to lack of industry support or acceptance by the computer science community, is not obfuscated. Thus this category does not list Pascal, Modula, Ada, or C#. Obfuscated languages are of two types, those that are: (1) Nothing more, or less, than elaborate jokes; example: Intercal is not much more than a thinking person's diversion, albeit a hilariously funny and impressively creative one. (2) Thoughtful and systematic explorations of the subtleties of programming language and algorithm design, or of the theory of computability.
Related categories 3
Strange Befunge-descendant language.
Comment Programming Language
An open-source language for writing comments.
DM's Esoteric Programming Languages
D. Morgan-Mar esoteric languages Chef, Haifu, Ook!, Piet, Whenever. Links.
Esoteric Non-existent Standards Institute
"Institute" for the standardization of unstandardized standardizable things, mostly esoteric languages and extensions to them.
Esoteric Programming Languages Ring
An organisation started to spread insanity and weird programming paradigms among the masses.
Collection of esoteric programming language implementations, examples, and related files.
Programming language with two main goals: confusing everyone with an obfuscated syntax, and designing as powerful a language as possible with a tiny implementation: this compiler executable is only 1024 bytes, written in pure 68000 assembler.
Malbolge: Programming from Hell
Specifically designed to be extremely difficult to program in.
A programming language in which program flow can go sideways. Closely related to Befunge. Tutorial, reference, sample source code, Public Domain implementation available.
Obfuscated Weird Language: character-based language interpreter written in C, in the style of False. By Antonio Maschio.
Home of esoteric programming languages such as Java2K, Smith#, Sorted!, , Esogotschi and the Great Python Language Zoo. Also heavy on the code obfuscation front.
Programming in Malbolge
Introduction to Malbolge programming. Also propose modificatins of Malbolge for making programming in it more worse.
Q-BAL Programming Language
A queue based programming language. It's not designed to be useful, just fun.
A language with beautiful source code that resembled Shakespeare plays.
The Unlambda Programming Language
Minimalistic functional language based on the Lambda calculus but lacking the Lambda operator. Tutorial, reference, GPLed interpreters available.