Greasemonkey is an extension to the Firefox web browser, which lets you run userscripts on your web pages.
Userscripts are scripts that run in the web browser, making on-the-fly local changes to specific web pages. In this context, they generally augment MusicBrainz pages and/or facilitate editing. You will usually need to install both a userscript runner (e.g., Greasemonkey) and also to install the scripts themselves in your browser before they will work.
See Guides/Userscripts for a list of userscripts which MusicBrainz editors have found useful.
Greasemonkey 4 incompatibility
As of February 2018, if you use Firefox browser version 57 or later, and the corresponding Greasemonkey version 4 or later, you may find that several userscripts popular with MusicBrainz editors do not work. The userscripts may eventually get modified to work with Greasemonkey. Until then, the best advice is to use either Tampermonkey or Violentmonkey instead of Greasemonkey.
For more information, see the Greasemonkey 4 Announcement, 20 Sept 2017:
- With the upcoming Firefox 57 release, … Mozilla is completely replacing the extension system in Firefox… As a result, version 4 of Greasemonkey is a nearly complete re-write. … A variety of compromises have been made. We've elected to make a rare backwards incompatible change.
And, Greasemonkey 4 For Users, 20 Sept 2017:
- …this will break some scripts. If you rely on such scripts, you might want to install Violentmonkey or Tampermonkey, both of which provide better compatibility for existing scripts.
- Wikipedia article on Greasemonkey
- Greasemonkey web site: http://www.greasespot.net/
- Search "How to install userscripts": https://duckduckgo.com/?q=how+to+install+userscripts