ClojureScript is the most-used functional language that compiles to JavaScript
I dislike all compile-to-JavaScript languages. The compilation step is a massive overhead and it becomes a major pain in the neck once your project reaches a certain size.<p>Whatever shortcomings of JavaScript these languages claim to solve are not worth the pain and suffering that this extra compilation step adds.<p>They all claim to compile really fast, yet whenever I have worked on a project which uses a compile-to-js language, they always seem to end up taking 10 to 30 seconds to compile each time and this slows down debugging significantly.