Impressive JavaScript framework for building apps that look like desktop apps. It implements a version of Objective-C in JavaScript and then builds a Cocoa-like framework on top of that. (tags: programming web web2.0 language javascript)
This clear and concise explanation of CSS stacking contexts explains how the CSS z-index is not just a simple linear dimension, but there can be multiple nested stacking contexts. (tags: tutorial css web reference)
Impressive implementation of the Processing animation language in JavaScript (tags: programming javascript graphics code language web library)
Interesting Java applet that displays web page DOM trees as colored graphs. (tags: design)