Infinity.js [gos.i, homepage] is a UITableView for the web: it speeds up scrolling through long lists and keeps your infinite feeds smooth and stable for your users. It is small, battle-tested, and highly performant. The code is hosted on Github, and distributed under the BSD License. The annotated source is available, as are demos both with Infinity turned off and on.
perl -pe); pipelining; pretty printing & more.
spin.js [gos.i, homepage] is an animated CSS3 loading spinner with VML fallback for IE. It uses no images & no external CSS dependencies. Highly configurable, resolution independent, and works in all browsers; including IE6.