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.Whatever shortcomings of JavaScript these languages claim to solve are not worth the pain and suffering that this extra compilation step adds.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.