Good question. They didn't answer it. Is the Scala code going to be much more compact? And what problems scaling JS to rich applications were they thinking of, exactly? They don't say.
The slides shown there are, well, slides. They are meant to support a talk, and that talk addressed your comments, at least partly. It is also worth noting that it was Scala Days, and as such I took it for (almost) granted that the audience is converted to Scala.
The problem is that JavaScript, with its scripting nature, has never been designed to support programming in the large. The lack of type safety is often mentioned as one of the major difficulties of JavaScript. That is why there are other languages targeting JavaScript.
We scale to Rich Internet Applications by using the language Scala, which is a scalable language. I won't try and make a whole point here. Some people have moved from Java to Scala for that very reason.
And, yes, the 16 MB are for the standard library. But minifying was only the first step towards reducing that size. I have at least 4 ideas, which I believe will each divide that size by ~2. That should bring it down under 1 MB.
Thanks for your reply. I would be interested to read the whole argument. I don't know what "scripting nature" is. JavaScript has first-class functions and is nearly syntactically identical to Scala. It doesn't have a type system, but I'm not convinced that's a problem for scalability. Java has a type system, and you say people are moving away from it because it's not scalable, so...
Definitely a strange mindset. How does JS not scale to rich applications? I'd rather use modular JS and a MV* framework than try to use GWT equivalents or things that compile to Java from other languages where the idioms don't translate.
Things are very very alpha at the moment. Yes, it's huge now but is going to change in the future. Don't get discouraged by this as it's nowhere near final production version.
"How to scale to Rich Internet Applications?"
Good question. They didn't answer it. Is the Scala code going to be much more compact? And what problems scaling JS to rich applications were they thinking of, exactly? They don't say.