Scriptish

Scriptish is a fork of Greasemonkey, which allows JavaScript to be run client side to modify the DOM model primarily to change user presentation, but also a host of other features, when running as a plugin to Firefox, or Firefox based browsers. Scripts were available for a wide range of functions from userscripts.org, later from greasy Fork. It was created by a contributor to Greasemonkey who felt that Greasemonkey was becoming stagnant.