01 What is the esoteric programming language Whitespace?

Whitespace (programming language) – Wikipedia

Whitespace is an esoteric programming language developed in 2002 by Edwin Brady and Chriss Morris. The commands are composed of the three characters “space”, “tab” and “linefeed” – the so-called whitespaces – non-printable characters.

For better readability the characters s, t and l are used also.