So you ended up with this JavaScript quirk where it was possible to create unique URLs that ran a bit of JavaScript on whatever page you happened to be looking at. It could even make changes to that page. Move things around. Replace words. Open links. And pretty early on, people realized that these JavaScript URLs were also bookmarkable, just like any other URL.
And, crucially, easily shareable as links.
I had almost forgotten about these things.
I used those quite a bit, also greasemonkey, the real problem I had was that many websites started changing things more frequently. I had one that was very useful for me and my friends for facebook, but facebook stated breaking it more and more often, until I just gave up fixing it. I feel like now you kind of need a DSL for each web page. I was hoping that the semantic web/xhtml would actually happen and make this work much easier but no one building a site really cared about how others might want to change the appearance of it. If it was logical, that was mostly accidental. The design of a page, is optimized for building it, not changing it. In any case most complex sites are created in more abstract layers, then have the js output on the web the result of some sort of complication/minimalization which makes interacting with it more complex. If I mess with code now, its only if its an easy fix that doesn’t change often and has to require a change more difficult than just inspecting and changing with the developer tools.
Never knew they were called that. I use one to change Wikipedia to use the Vector skin.