If you're going to write large scale widgets, YUI is a better suited choice because of it's already large collection of A-grade supported widgets, and emphasis on reuse. Yahoo! has put a ton of work into making sure their widgets are accessible by the disabled.
In addition, YUI3 can dynamically load resources, which can be very beneficial if you have a large collection of widgets and only want to load the code for them when it's necessary.
I love both libraries, there are trade offs with each, which is why evaluating them for your project is a wise decision, if only to understand the strengths and weaknesses.
In addition, YUI3 can dynamically load resources, which can be very beneficial if you have a large collection of widgets and only want to load the code for them when it's necessary.
I love both libraries, there are trade offs with each, which is why evaluating them for your project is a wise decision, if only to understand the strengths and weaknesses.