Hi there - yes, it's partly about marketing message. When we did early validation, people were concerned about a 'custom language' - the reality is that the majority of the application is written in JS - the performance parts are in KL. KL itself is almost identical to JS, but right now you have to declare types. In the future we may switch to inferred types, at which point code will be indistinguishable from JS. Just don't use closures :)