Greasemonkey add-on for Firefox brings user opted changes in webpages simply by installing user scripts. It is one of the most popular add-ons for Firefox. We have also seen that few user scripts can work with other browsers (like Opera, Chrome etc.) as well.
The developers of Greasemonkey add-on are now working on some big changes in user interface. Anthony Lieuallen has his roadmap ideas for the next version 0.9. In coming version, list of user scripts will show up in a pane of the default Add-ons window, rather than the “Manage User Scripts” dialog of current version.
If you want to try preview build of GM 0.9, you can download the xpi file directly from here.