What is "userscripts"

Userscripts refers primarily to extensions javascript used in web browsers. Userscripts automate and customize actions and/or change the layout (can completely transform a website of others). Userscript can be configured to target specific domains or act globally on all browsed pages.

Userscripts are available in most browsers:

• Opera: Supported through the extensions Violent Monkey and Tampermonkey beta.
• Firefox: Supported through the add-on Greasemonkey.
• Google Chrome: Natively supported (Greasemonkey scripts are supported by the extension Tampermonkey).
• Internet Explorer: Supported through the extension Trixie.
• Safari 4-: Supported after installing SIMBL and Greasekit.
• Safari 5+: Supported through the Ninjakit (Japanese website, English download link).