plasticmillion writes "Greasemonkey is a revolutionary Firefox extension that many feel has enormous implications for the future evolution of the web. By making it easy to write client-side scripts that modify webpages as you surf, it shifts the balance of power from content creators to content consumers. Since its inception, it has given rise to an impressive array of scripts for everything from enhancing Gmail with one-click delete functionality to preventing Hotmail from spawning new windows when you click on external links. In recent Greasemonkey news, Mark Pilgrim just published a comprehensive primer called 'Dive Into Greasemonkey', a must-read for those who want to try their hand at writing their own scripts. It should be noted that Greasemonkey is not without controversy, but this has done nothing to reduce its popularity among web programmers. Even Opera has jumped on the bandwagon with their own version of user scripts. To illustrate the principle to /.ers, I whipped up a handy little script called 'Slashdot Live Comment Tree', which lets you expand and collapse entire threads in an article's comments."