Note that plugins are more correctly called Extensions or add-ons. According to this page on Mozilla developer center:
Extensions are different from plugins, which help the browser display specific content like playing multimedia files. Extensions are also different from search plugins, which plug additional search engines in the search bar..
Interestingly, For GreaseMonkey fans or users, there's also the possibility of tinkering with the interfaces of the Google services (Eg. Google mail) using Google's Experimental GreaseMonkey API. This allows you to literally re-organize the service as you see it. Another reason to just love Google! The best part of this arrangement is that all it uses the Javascript syntax and is written in a text file (.JS) using your favourite editor, making it a breeze to prototype and even maintain. Here's a example script to give you the general idea.
If you come up with some interesting scripts or add-ons, dont forget to post a link as comments. I am sure me and other readers will enjoy, both, looking through and using them :-)
See also:
- Another good article on writing Firefox plugins from Lifehacker.
- Writing offline applications for Firefox 3.0
- And on Mozilla Developer Center
- Extension FAQ
- (slightly outdated) Creating Custom Firefox Extensions with the Mozilla Build System
- Subscribe to the Mozilla about:addon newsletter
- and so on..
- Google Code: Gmail GreaseMonkey Api
- IBM Developerworks: Integrate Encryption into Google Calendar with Firefox extensions
- Marco's accessibility blog: 5 Things to make your extensions even more accessible
- Although not for Firefox, but here's also how to write an extension for Google ChromeNew