Based loosely on Adobe’s ActionScript 3.

and

This was the starting point for much of the work which became known as ES4.

I’ve had trouble tracking down specific dates, but what I’m saying is that I believe ES4 was started first. Features from early drafts of ES4 were put into AS3 hoping that it could stay compatible. The article is saying that AS3 was created independently and then ES4 used it as a starting point which I think is misleading.

That said, Adobe has been a major contributor to the ES4 spec, so I imagine that many of the same people worked on both.

I should think that this is somewhat inappropriate for a piece that is selling itself as some kind of authoritative source for definitions. It didn’t seem quite funny enough to be obviously a humour peice (which would excuse the use of personal opinion) But I don’t know, I might be missing something. It seems quite dubious to intentionally mislead confused people like this.

The difference between ES4 and ES3 would have been similar in scope to the difference between PHP4 and PHP6 and perhaps also between Perl5 and Perl6. They all represent entirely new ways of handling complexity (classes with real semantics and syntax) but keep much of the flavor of their predacessors.

Insofar as ES4 introduced *both* classes and types to the language as well as packages and namespaces, it was a huge set of potential changes. I don’t think anyone who would call it a “new language” was being prone to hyperbole. It really was a gigantic set of changes.

Harmony *might still* be a gigantic set of changes, and it may also wind up being a “new language” in the same sense. What’s settled now, though, is that it won’t introduce packages or namespaces and that much of the class and type semantics, structure, and construction are up for a re-think. Insofar as those were the bits that would have defined ES4, it’s a big change.

Regards

It seems to have worked to such a frightening extent that they were forced to change the name of Ecmascript 4 to Ecmascript Harmony, just to shake off the bad vibes.

the paragraph in question is:

ActionScript 3.0 is compliant with the ECMAScript Language Specification, Third Edition (ECMA-262). It also contains functionality based on ongoing work on ECMAScript Edition 4, occurring within the ECMA standards body.

Much of this is true. AS3 is *nearly* compliant with ES3 (aka: ECMAScript 262-3), however it has no support for dynamic code loading or for eval(). This leaves it able to start up somewhat faster but means that it’s not really the dynamic language that JS hackers know and love. The relationship between ES4 and AS3 is very direct by I think the timeline which is implied there is in some doubt. Adobe contributed much of the work that had gone into AS3 for consideration by the ES4 working group, and much was (up until last week) on target to be accepted. I don’t work for Adobe and don’t know whether the chicken or the egg came first. Regardless, Adobe had been tracking the standards process with their language and I hope that commitment continues as the shape of Harmony becomes clearer.

Regards

http://www.adobe.com/devnet/actionscript/articles/actionscript3_overview.html