It is, therefore, that I find it interesting that when Crockford was on Channel 95 Live for MIX 20116 yesterday, that when he suggested YUI, it responded in so much surprise and nascent criticism from the many, many jQuery proponents inside of the Microsoft Developer community. The comment is hardly a surprise, and not because the Crock-en7 works for Yahoo! He's not on the YUI project, and while I'm sure he participates in code reviews, his name does not appear in the commit history of either YUI2 or 3. He has, however, been critical of jQuery and it's creator, John Resig8, in the past, often making snide remarks about 'ninjas'.
But these weaknesses were all identified, and by the time I'd started using YUI2, YUI3 was already in it's design phase, and when it's first previews were released, I knew it was something special. It brought Loader, a tool I was intimately familiar with from YUI2, into the forefront making it simple to use. It defined a set of building blocks that promised to make widget creation, perhaps not trivial, but dramatically easier. It integrated CSS Selectors, the killer feature that everyone was so excited about in the jQuery world. It provided a plugin and custom event architecture that allows for easy composition and customization in a way that I hadn't seen in any other library.
To this day, many of the Widgets in YUI2 haven't been released in the Core of YUI3 (though many of Gallery11 counterparts of varying levels of functionality and quality), which a many people see as a weakness. However, this is similar to how other projects operate, where the UI Widgets are a different project from the internal core, and that's great. The fact is that there are more people building cool things for YUI3 than ever were for YUI2, and for those that have worked in other libraries, they almost all say that they find it easier and faster to build their code than in the other options available.
It is sometimes frustrating that the tools I want don't always just exist, or perhaps aren't quite right, but I have found very few problems that I haven't been able to prototype in at most a few hours of work using YUI3, including the first run of my attempt to re-think multiselect. Of course it takes longer than a few hours to polish the idea and make it shine, but rapid prototyping is immensely useful. Plus, for a well-polished widget that does, say, 75% of what I require, it is easy using the framework to extend the behavior I require without needing to directly modify the code for the core widget. There are exceptions to this flexibility, but they are definitely the minority in my experience.
I don't anticipate that this will directly buy any converts. I have shown no code. I have made comments that will likely offend someone. This post is more a collection of my thoughts on how I ended up using this particular library, and why, when I leave my current position, I'll continue to advocate for YUI wherever I end up. I am not so inflexible as to refuse other options, but I like to use tools that I know are a good idea, and not just ones that look like it12.