The terms framework and library in the context of JavaScript are often used to communicate the same meaning. However, in our opinion, the meaning that these terms share is negligible compared to their differences. As such, we believe they both have an important and different meaning that should be clarified.
For the sake of communication (not for the purpose of being right), the authors of JavaScript Ant have agreed on the following meanings.
JavaScript Library -- Repository of useful JavaScript code that enhances and simplifies core JavaScript programming as well as programming JavaScript for a web browser.
Examples: jQuery, YUI, DOM Assistant, Mootools, Dojo, Prototype, EXT.
JavasScript Framework -- Frameworks typically use code libraries as a base, but will also include a set of UI patterns or widgets that depend upon javascript code that typically generates, manipulates, dictates, and restricts how a UI functions.
Examples: jQuery UI, YUI, Dojo, EXT, Backbase, OpenLaszlo, Qooxdoo, Bindows.
Another way to think about it is that a framework will typically always use a library, but not all libraries are also frameworks.