This is the HTML version of the Open Web Tools Directory, a Mozilla Labs experiment to catalog the expansive universe of tools related to creating web applications based on open standards.
XML.com, where the XML community shares XML development resources and solutions, features timely news, opinions, features, and tutorials; the Annotated XML specification created by Tim Bray; authoring tools, XML developer resources, interactive forums...
Experiments in web programming. Features articles, tutorials and example code related to client-side and server-side web development. Heavy on the standards.
The Yahoo! User Interface (YUI) Library is a set of utilities and controls, written in JavaScript, for building richly interactive web applications using techniques such as DOM scripting, DHTML and AJAX.