Although my JavaScript development focus is currently on the Yahoo! User Interface Library (YUI) I do try to keep up with some of the other libraries. Here I'll begin to offer up my recent notes and observations on five popular projects, Dojo, Ext JS, jQuery, Moo Tools, Prototype/Scriptaculous, and YUI.
A common occurrence in Web 2.0 sites, and one that a recent Pingdom study notes, is the concurrent use of multiple JavaScript libraries. One explanation for this is that a required (more often desired) feature or widget may appear to only be available within one specific library.
In my previous article we traded in old school JavaScript habits for unobtrusive methods and the Yahoo! User Interface Library (YUI). The YUI's Event and DOM extensions greatly simplify basic DOM scripting tasks. Let's build on this foundation and improve the rollover script's performance and scalability.