Mozilla to focus on Jetpack and Personas - Update
Mozilla is planning to change the way that users extend Firefox. The older Extensions and Themes, also known as add-ons, are to be superseded in the long term by Jetpack and Personas, both recent Mozilla Labs projects. The announcement came in a posting from Mozilla's Mike Connor, a lead Firefox developer, who says there is a consensus for the move within those guiding the project at Mozilla.
Connor says that he expects developers to migrate their extension development towards using Jetpack and that the current Extensions should be considered deprecated. He added that this was a "strategic product decision", but the change does not mean that the older Extensions were just going to disappear; the goal though is to "drive everything that can be moved to Jetpacks to that model, because it's a better model for developers". This in turn would drive the development of Jetpack's API development. "Whether in a couple of years we are willing to say that the old model is well and truly unnecessary is crystal ball gazing at best" added Connor.
Personas supersedes Themes, in the same way as Jetpack supersedes XUL based Extensions; a more modern replacement. Personas, as currently integrated in Firefox 3.6 RC1, makes it simple to change the appearance of the Mozilla browser, but, like Jetpack, does not offer a complete replacement for the functionality of Themes. For example, Personas cannot currently replace toolbar buttons, but the developers are working on adding that capability.
Update - In a post on the Mozilla Labs Blog, the Mozilla developers have clarified previous comments and now say that no decision has been made about deprecating the existing XUL based extensions system.