> have you actually tried to write something in javascript?
yes. I'm the author of KFM as well as a few little tricks
> what works in one browser doesnt work in another...
jQuery, ProtoType, MooTools, Ext, etc
> the number of simple functionalities that are
missing sleep() for instance?
can be emulated with setTimeout().
PHP has array_merge() but C doesn't. Does that mean that C is crap?
> and its only just recently got threading support
again, could be emulated with setTimeout(). Even for() loops can be broken apart ("threaded") using a bit of thought and setTimeout().
Just because JavaScript doesn't have the same list of tricks that some other languages have doesn't mean it's not worth using.
My opinion is that if there is a language which you /know/ is available on every browser that people use (normal people - not 'noscript' users or web crawlers), then I don't see the problem in using it.
To bring the context back to the article, I've had that idea before, about letting a bit of computation happen on the browsers of people reading my own sites. That could not happen if a big popup announced that a script was trying to run in a plugin not supported by the browser (ActiveX, Java, Silverlight, Flash). Why not just use the language that is there...
I mean, if your requirement is a language that might not be present in all visitors' browsers, then why not go the whole hog and ask the reader to download and install a full application?