Web: Now this is very cool stuff: ‘Greasemonkey is a Firefox extension which lets you to add bits of DHTML (“user scripts”) to any webpage to change it’s behavior.’
In other words, you can rewrite any page viewed in Firefox, as it transits between the server and your client’s display; a form of transcoding.
Traditionally, transcoding is performed using a HTTP proxy which applies the transformation, or a specialised HTTP user agent which transcodes and outputs a whole new set of documents with the results.
That was all a little hacky for full-scale integration into your web browser, though, so Greasemonkey is a big improvement for that use-case.
Some good links:
- The Greasemonkey homepage
- The Greasemonkey script repository (wiki)
- Mailing list archives for greasemonkey users
And some demos:
- a good demo of using it to fix a Bloglines bug, by Michael Moncur
- an MSDN bug-fixing script
- a Boing Boing ad-blocking script
- truly awesome: persistent searches (think vFolders) in GMail!
Remember, these are single, sub-100-line JS scripts, running entirely locally in the user’s web browser. The last one gives you an idea of what coolness is possible…
My contribution: an ad-removal script for Metafilter. It took some 30 seconds of hacking to produce this — soooo easy. It’s a whole new world of site customisation and hackable filtering. You thought AdBlock was good, this is ever niftier ;)