Esoteric programming language

Esoteric programming languages are programming languages which usually have unusual or strange syntax and functions. These languages are usually created as a joke, to be different, or as an art project. While they can often run programs, they are not usually used to create real-world applications; instead they are used to create puzzles or be studied by computer scientists. Examples of esoteric programming languages might be Brainfuck, ><>, and Malbolge.