OpenLisp
OpenLisp is a programming language that is a dialect of the Lisp family. It is primarily used for functional programming, symbolic computation, and artificial intelligence applications.
Hello, world code example:
#!/openlisp/uxlisp -shell
(format t "Hello world!~%")
(print "Hello world!")
Popularity: Less than 1% of developers are using or have used this language.*
*According to StackOverflow's 2023 survey.