This document discusses the benefits and potential of Firefox extensions. Extensions can powerfully modify webpages, open new marketing channels through the Firefox marketplace, and fortify companies' market positions by integrating directly into the browser. Well-designed extensions can fundamentally change assumptions about the web by enabling new functionality and ways of interacting with information across sites. The document encourages exploiting the innovation possibilities of extensions, as there are still many untapped opportunities, while noting some technical and legal challenges that developers should be aware of.

1. The Joy of Firefox Extensions Andy Mitchell andy.meecard.com Meecard.com – A snippet of youness online

2. Let’s do introductions… http://gtdinbox.com http://webcards.whymicroformats.com

3. A Firefox extension? That would be anything that extends the browser to create a new UI or modify pages

4. Why are they so great?

5. They are powerful… This is GTDInbox adding task management to Gmail. The power is the ability to modify any webpage. Audible.com once made an unpopular (bad usability) site redesign; and the users revolted. They used Greasemonkey to revoke the old design.

6. They open new marketing channels… Mozilla actively pushes extensions to their massive userbase. The potential for innovation means blogs will voluntarily spread the news about cool extensions.

7. They fortify market positions… Google et all fear the competitor is only ‘one click away’ By installing themselves into the browser, they become the first choice for a user. The value of this idea provided the bulk of Mozilla’s $53,000,000 revenue in 2005 (paid by Google to appear in search bar)

8. They change fundamental assumptions about the Web… Extensions like Operator and WebCards do ‘information broking’ They move previously ‘locked’ data between sites For instance, they could move a contact from LinkedIn to another social network with a few clicks

9. They open up completely new possibilities… StumbleUpon monitors your browsing habits to infer ‘taste’ It then matches you with similar users… And makes recommendations that let you discover completely new topics & sites A concept made viable only by being a browser extension

10. So, what’s the point? Exploit Innovation! A Firefox extension is powerful and easy to develop. They are relatively untapped – not that many people make them. Therefore there is still the ability to stand out – to innovate. And with innovation comes attention. The nett effect is better for you (& whatever else you’d like to promote), and better for us users!

11. Are there any drags to all this? Firefox gets updated and has been known to break extensions. Different platforms can behave strangely. And, if you interact with a site, you have to update every time it does. The bottom line is that extensions require maintenance.

12. And dangers? Yes, the legal issue. My first extension could put eBay inside Amazon and Amazon inside eBay. On the one hand, arguably no different from one of the dozens of price comparison sites. And, one could claim it is just another way of rendering a site (just as IE/Firefox each render differently). But do you really want to go to court against someone like Amazon to prove it?? Be sensible in what you choose!

13. The Mechanics of a Firefox Extension… Javascript controls everything XUL to create new browser-based UI (it’s a lot like HTML) One file to kick start it all: the ‘overlay’ (loads on every page) Greasemonkey abstracts many common problems if all you want to do is minor tweaks to pages. It allows you to very easily execute Javascript in any page – e.g. to add a button, or remove a banner.

14. Useful References http://developer.mozilla.org/en/docs/Extensions http://kb.mozillazine.org/Getting_started_with_extension_development http://greasespot.net/ http://www.rietta.com/firefox/Tutorial/overview.html (Just search Google ‘ develop Firefox extensions ’) Also, all extensions are open source (download, rename .XPI -> .ZIP and extract the source) Learn from others!