How would you like to be able to customize the layout of the Google homepage? How about add better video controls and a download button to YouTube? Or set a profanity filter that works across all websites? Maybe remove all the “What type of leafy vegetable are you?” quizzes from Facebook? These are very few of the things that can be done with Greasemonkey. By itself, Greasemonkey does essentially nothing. At least, nothing that you as a user would notice. To really use it, you download Greasemonkey scripts which all have some special purpose. For example, right now I’m writing this from a browser with Greasemonkey installed, and I’m using scripts to enhance YouTube, Facebook, and Google Images.