yui or yui3

Question

Is YUI3 ready mature enough? What are its advantages and disadvantages compared to YUI?

Answer 1

@Corwin is incorrect about files changing on the yui.yahooapis.com servers -- if you use the YUI 3 PR 2 release from our servers, those files will remain there even when subsequent releases come out.

It's true that the API will change some as we move toward beta 1 (scheduled for June) and then to GA. We will undoubtedly make changes that will require your attention and time as you upgrade. That -- and the fact that YUI 3 doesn't contain all of the functionality of YUI 2.7.0 (the current release in the 2.x codeline) -- is the primary reason to hold off right now.

You can learn more about YUI 3 and how it's different from 2.7.0 here:

http://video.yahoo.com/watch/3711767/10207432

We're using YUI 3 on the next version of Yahoo's homepage. You can read about that here:

http://yuiblog.com/blog/2008/11/11/frontpage-and-yui3/

Answer 2

I've been using YUI3 exclusively since the PR2 release. There has been a lot that has changed since then, but my specific application code didn't have to change too much. I have also been tracking all the major changes in YUI3 during the past months.

It's now June, and things appear to be coming close to beta 1 as I'm seeing a ton of documentation related commits. I would recommend using YUI3 over 2 if you're looking for very nice, feature-rich base JavaScript library. If you need a bunch of generic widgets, it is possible to have both YUI2 and YUI3 running together, although things will be complicated and your code will be using mixed APIs; but you may want to stick with YUI2.

YUI3 is becoming a pretty great library and framework, it has matured greatly in functionality, performance, and cohesiveness since PR2.