Parenthetic

The parenthetic programming language is a functional programming language that (like Parenthesis Hell) uses only parentheses in its code. All other characters are considered comments.

The language works by interpreting certain parenthesis sequences as symbols (for example, the sequence  corresponds to the add function). Currently, parenthetic supports the following commands: define, lambda, if, not, <=, equal, + - * /, cons, car, cdr, and conversions between lists and strings.

Examples
Hello World: (()(())((())(())((())(()) (()))))(()(())((()())(())))((())((()())((( ))(())(())))((()())((())(())(() )))((()())((())(())(())))((()())( (())(())(())))((()())((())(())( ())))(())((()())((())(())(( ))))((()())((())(() )(())))((()())((())(())(())))((()())((())(())(() )))((()())((())(())(()))))

External resources
Official parenthetic page on Github