Pharo
Pharo is an open-source object-oriented programming language that is a dialect of Smalltalk. It is primarily used for developing software applications and systems.
Hello, world code example:
"Comments are in double quotes"
"Sending message printString to 'Hello World' string"
'Hello World' printString
Popularity: Less than 1% of developers are using or have used this language.*
*According to StackOverflow's 2023 survey.