Greasemonkey for Firefox is an add-on that allows users to install scripts that make on-the-fly changes to web page content after or before the page is loaded (also known as augmented browsing).

Customize the way a web page displays or behaves, by using small bits of JavaScript.

The changes made to the web pages are executed every time the page is viewed, making them effectively permanent for the user running the script.

Greasemonkey can be used for customizing page appearance, adding new functions to web pages (for example, embedding price comparisons within shopping sites), fixing rendering bugs, combining data from multiple web pages, and numerous other purposes.

With Greasemonkey for Firefox, you can write scripts or choose from the many scripts that already exist.

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