I don't see what Ext Core - which is released under the MIT license! - has to do with the GPL license of the Ext JS library.
Nobody has to pay for using Ext Core, so the only valid reason for not choosing it is a dislike for its syntax, internal workings or any other technical reason.
It's the same reason people are suspicious when Microsoft associates itself with open-source software. Past actions make people suspicious as to whether they can rely on them for support in the future, especially when it comes to something like frameworks where large code-bases rely on its continued existence and the vendor not pulling the plug, and kill any ill-will in the community.
So your definition of hard-working, talented developers trying to create quality products, while trying to be able to keep doing this by selling a license for commercial projects not wanting to use the GPL license (note that GPL is as open-source as code can get) is "the shame of software development and ethics". I was about to write a detailed reply, but after rereading your comment a couple of times, I think there is just no point in arguing with someone who obviously doesnt know what he is talking about, and is obviously meaning to offend others by making untrue and hurtful statements.
Besides that, The Ext Core library is released under the permissive MIT license, and I'm confident in saying that that won't change in the future.
History shows that the license change was an attempt to find a business model. (they already had commercial licenses with the lgpl - maybe no one was buying?) If you interpret this as being untrustworthy, then so be it. These guys are doing amazing work and to question their ethics, when you obviously don't know them, shows a bit of immaturity on your part.
Edit: Oh, I see you removed your post ;) I'll leave my reply on here anyway for people interested in what the Ext.select element does.
Actually you can't use CSS selectors with the Ext.fly method. I think you are confused with the Ext.select method, which returns a CompositeElementLite instance containing an array of all elements conforming to the specified CSS selector. It lets you perform operations on a collection of elements as if you are using a single element. This is very close to what the jQuery $('.some-selector') provides you and works by iterating over the elements array and swapping the DOMElement pointer on an internal Flyweight instance right before it executes the operation on that Flyweight, and thus performing the operation on each element.
Ext.fly uses the Flyweight pattern, which basically means that instead of creating a new instance of Ext.Element to wrap around the DOM element, it uses one global instance of Ext.Element and just simple replaces the internal pointer to the DOM element within that instance. This makes it faster because it can skip constructor and additional logic to create the Ext.Element instance, and smart because it doesnt need additional memory for a new instance. To read more about the Flyweight pattern, you can read here: http://en.wikipedia.org/wiki/Flyweight_pattern
Hey, I'm the author of this library. To be honest I have never tried to use ExCanvas or any other Canvas replacements scripts for IE with this library because I supposed it would run really slow. Thanks for the tip, I'm going to try it out.
I worked on this several months ago and never really had a second look because of lack of time. New job and all. I always wanted to come back to this though and polish some stuff like sound support (would have to be flash i guess), mouse support, some optimizations (did some tests creating space invaders and found some very real possible improvements, by for example using the experimental canvas.drawString available in some of the nightlies of (proper) browsers), and some other minor quirks.
If anyone has any questions or just wants to discuss something with me about the internals or possibilities, you can contact me at tommy@extjs.com
Nobody has to pay for using Ext Core, so the only valid reason for not choosing it is a dislike for its syntax, internal workings or any other technical reason.