What Is AJAX - A New Approach to Web Applications, by Jesse James Garrett, the person who coined the term 'AJAX', shorthand for Asynchronous JavaScript + XML.
XAJAX - xajax is an open source PHP libary for building Web-based Ajax applications.
AJAX Patterns - A collection of design patterns advising on usability and technical implementation of Ajax applications.
Web 2.0 Technologies
What Is Web 2.0 - Design Patterns and Business Models for the Next Generation of Software, by Tim O'Reilly.
Rico - An open-source JavaScript library for creating rich Internet applications.
moo.fx - moo.fx is a superlightweight, ultratiny, megasmall javascript effects library, written with prototype.js.
Lightbox JS - Lightbox JS is a simple, unobtrusive script used to overlay images on the current page.
script.aculo.us - script.aculo.us provides you with easy-to-use, compatible and, ultimately, totally cool JavaScript libraries to make your web sites and web applications fly, Web 2.0 style.
Prototype - Prototype (widely known as "prototype.js") is a JavaScript framework that aims to ease development of dynamic web applications.
eBay Technologies
What Is eBay - eBay is The World's Online Marketplace® for the sale of goods and services by a diverse community of individuals and small businesses.
eBay Developer Program - The eBay Developers Program provides access to the eBay marketplace through Web services so you can create software to make selling and buying on eBay even easier.
eBay Affiliate Program - The eBay Affiliate Program is a community of Webmasters, Internet developers, and entrepreneurs who promote eBay and earn commissions while doing so.
eBay Buying & Selling Strategies - eBooks written by eBay Pros who can show you how to buy and sell just about anything on eBay's Auction site. Learn the secrets from the pros and start making money now!
Zillow Technologies
Zillow Open API Program - Zillow’s open API will allow a third party Web site to recreate a lot of Zillow’s functionality on their domain. Includes Zestimates™, Zindex™ info, charts, comparable sales (including sales date and price), beds/baths and other data.