JavaScript libraries usage amongst the top 1000 sites: 1. jQuery, 2. YUI, 3. Prototype, 4. MooTools.

56% of the sites that use the Yahoo User Interface (YUI) library are also using vBulletin as CMS.

The YUI Library is the most popular JavaScript library on Arabic websites.

The YUI Library is the second most popular JavaScript library amongst the top 1,000 sites, far behind JQuery.

The YUI Library moved one rank up to #4 in the JavaScript Library survey

The Yahoo! User Interface Library is steadily gaining popularity amongst JavaScript developers.