Dynamic HTML and XML: The XMLHttpRequest Object

xajax PHP Class Library - The easiest way to develop asynchronous Ajax applications with PHP: "xajax is an open source PHP class library that allows you to easily create powerful, web-based, Ajax applications using HTML, CSS, JavaScript, and PHP. Applications developed with xajax can asynchronously call server-side PHP functions and update content without reloading the page."

Programming Texts/Tutorials: "A list of freely available documents (i.e. tutorials, books, guides, reference manuals, etc.) for learning how to program in various languages as well as about various Linux and UNIX related topics."