A long while back Mozilla began experimenting with a brand new way of writing extension for the Firefox, and called it JetPack. It was intended to make it easier for developers to create extensions for Firefox, and make the development processes easier for newcomers, faster and more stabe.
[RELATED_ARTICLE]With JetPack Mozilla intended to provide a completely new extension format that would be restartless, and would require extensions written in web standard technologies such as JavaScript, HTML, and CSS instead of Mozilla’s own home grown XUL. Mozilla would create an API for interacting with Firefox features and keep said API stable across changes in the browser as newer versions wold release. This was to become the preferred way of writing extensions for the Firefox platform.
However, after a while Mozilla changes the approach they were taking, and instead of a new extension mechanism, they created a new SDK for creating extensions which would allow for the same features and benefits that the original JetPack prototype did, but where JetPack based extensions could be written is HTML CSS JavaScript and be converted by a the SDK to a Firefox extension. To this end they started the JetPack SDK.
Finally the JetPack SDK has emerged as a beta product known simply as the Add-on SDK 1.0b1. As Mozilla claims, this is not a feature complete beta. The Add-on SDK has been through 10 alpha stages as the JetPack SDK, during which the extension API has changed considerably. With this release the API is finalized, however Mozilla will add features and make small non-breaking changes over time.
The Add-on SDK has been designed to ensure that add-ons created using today’s SDK will play well with future technologies that Mozilla introduces. For example, Mozilla plans to make Firefox more like Google Chrome, by displaying web content in different processes. Each tab and extension could then work in a separate process just like in Google Chrome.
Hopefully with a simpler way to create extensions, more developers will Flock to Firefox. Changes to Firefox in Firefox 4 mean that even add-ons developed without the SDK can be made restartless, and you will find such extensions steadily increasing in number. Despite the Add-on SDK it is will still be possible to develop extensions for Firefox using the old methods (XUL JavaScript) and that might continue to be the route taken by some of the more complex add-ons ‒ especialy those that have binary components.
Already the number of extenions for Firefox is no small amount, and with Mozilla lowering the bar significantly the number of add-ons is sure to explode. Of course as it becomes easier to make addons, the overall quality of addons is bound to go down a little. In any case, the future looks bright for Firefox add-on developers.