Erlang (via Erlang Core) is actually quite a sweet example. Erlang (which is small) is transformed into Erlang Core (a language targetted at machines not humans) which has a very small set of primitives (21 in all). That Language is turned into a compact AST which is then transpiled to a Javascript AST and transformed back up to Javascript using standard JS syntax tools.
I have also written up the thinking about how to make an OTP-ish Erlang dialect in the browser work as part of Erlang/OTP's 'span of control' in the server-side cluster: http://luvv.ie/mission.html
Does it run on BeamJS? :D
[1] https://hacks.mozilla.org/2013/12/gap-between-asm-js-and-nat...
At the very least I'm unsatisfied with the rationale provided in the page. Other items generally explain what makes them worthy of this list, but async.js is just, "Async utilities for node and the browser" which is, while immensely useful, doesn't change JavaScript in a way that is shared by other items on the list.
Right now I'm having a lot of fun playing with Haxe and OpenFL/Lime (formerly NME). Being able to create an app with the Flash-like API and compile it, without modifications for HTML5/Flash/Windows/Linux/Mac/Android/iOS/Tizen natively (!!) feels like some sort of unholy hack. Not to mention it's other abilities (compile to everything from JS to Java, C# and C++).
I personally find CoffeeScript very useful, and believe it's sufficiently widespread and mature as to be viable. All of these others though, I can only see it as increasing the learning curve on a project. I want to use IcedCoffeeScript (Oh, am I tired of Promises) and some of the JS extensions but I can't justify it. It's like a cake that I know I can't eat.
Not sure what this means? If there is a existing project, it would probably be better to do JS. If you start a new project, or you want to change the language then you move forward with the new language and slowly replace or just keep using the old JS.
> (Oh, am I tired of Promises)
Insted of just adding Await and Defer, when you switch to ClojureScript, you will get full CSP semantics, full first class channels, essentially what Go offers on the server.
Check out this blog, it mostly talks about the difference between different ways of front end programming, callbacks, CSP and so on: http://swannodette.github.io/
I'm not saying JavaScript is good or bad. Just saying that there is certainly a strong desire to not write it, as evidenced by this long list of transpile languages.
