GAP is a programming language for computational discrete algebra, with a focus on computational group theory and computational representation theory. It is often used as a research tool in mathematics and computer science, particularly in the areas of group theory, algebraic combinatorics, and computational algebraic geometry.

Hello, world code example:

# Several ways to do it
"Hello world!";

Print("Hello world!\n"); # No EOL appended

Display("Hello world!");

f := OutputTextUser();
WriteLine(f, "Hello world!\n");

Popularity: Less than 1% of developers are using or have used this language.*
*According to StackOverflow's 2023 survey.

Repositories on GitHub: 4,465