There and Back Again

Behavior works by using css selectors to add javascript code to DOM elements. You create a hash of css selectors and functions that take an element add onclick etc JavaScript. You then register these rules against a page and matches them against there matching DOM elements and the JavaScript code is added. The code is designed in a way that you can treat these rule files just like style sheets so all the page using them needs is an include. Behaviour's goal is to remove the heavy use of onclick attributes and script nodes from pages so they aren't messing up content. It works well and can help make your JavaScript more reusable since its more centralized.

domTT while providing tooltips also provides a number of related features such as custom content menus or fake popups. Very featureful library with good examples of each feature and option.

Quick introduction to javascript and a short example on howto setup XMLHttpRequest and make a request with it.

Article focuses on form validation, the standard case of signing up a new user and finding a unique username is used. Backend is PHP producing xml which is consumed using the DOM on the javascript side. This is a very introductory aricle with XMLHttpRequest examples that would need some work for cross browser usage.

Cross-browser wrapper for native XML APIs. It offers various XML related goodies like Document instantiation, XML loading from URLs or strings, XSLT transformations, XPath queries. Provides an XMLHttpRequest wrapper thats supports synchronous and asynchronous operation.

A small (4kb) lightweight js library that provides drag n drop of dom elements. Website contains lots of examples to help you get started but also suggests its non-conventational and expirimental in setup. Doesn't seem to be actively maintained but its small enough it might just be feature complete.