(photo by Yahoo Developer Network)

Solutiongrove has been using YUI on the front-end since it was released in 2006. I fell in love with it's sophisticated handling of browser events and how event listeners put unobtrusive in "Unobtrusive Javascript".

We have seen it evolve from a couple of core utilities to a library with complex controls and widgets.

Just a few days ago the YUI team released a developer preview of YUI 3, the next generation YUI library (YNG, YUI Next Generation). 

I haven't had a chance to try it yet out but I'm pretty sure I will soon.

While I haven't had a chance to examine the code , I have had the opportunity to read up on the documentation and join the YUI 3 Yahoo Group.

So here are my thoughts and impressions so far :

• Many YNGs in a page
  
  • It looks like you can now instantiate more than 1 YUI in a page with each instance containing only the modules that you need
• Is it a rewrite ?
  • It seems like it. One indication is that the documentation is missing the list of controls and widgets on YUI 2.5. Instead you see an attributes and base component which will no doubt serve as the foundation for future controls and widgets
• The essentials are in core
  • Another indication that it's a rewrite, maybe from the ground up, is that the utilities that were previously stand alone like JSON and YUI loader are now integrated into YUI core.
• YNG and YUI can play together
  • The namespace has changed from YAHOO to YUI. This will ensure that there is no collission between YUI 2 and YUI 3 so one should be able to use both on the same page
• the YUI configurator (http://developer.yahoo.com/yui/3/configurator/)
  
  • If you ever wondered how much of your page is YUI code, this online tool is for you.
  • It calculates how much of your page is YUI code minified or in its regular form.