Remy Sharp dissects a piece of jQuery code pointing out the red flags. Each flag is taken in turn, explained and shown how to correct. Takes into account context and the flexibility of jQuery
LowPro is a scripting extension to Prototype written by Dan Webb to make unobtrusive DOM Scripting much easier. Included are an onReady event, adding behaviour using CSS selectors, fixing the this reference to always refer to the element within events, and a mechanism for triggering events.