. Mozilla touted the Jetpack 0.3 upgrade on Saturday.

"There are now over 60,000 people who are using the Jetpack platform to extend their browsing experience, and many of these Jetpacks have been written by first-time extension developers," said Atul Varma and Aza Raskin on behalf of the Jetpack development team, in .

Improvements include a revised API for SlideBars, which enable access to information at the side of a browser window. Mozilla also added the ability for a SlideBar to notify the user of an update in a non-obtrusive way. The SlideBar API in version 0.3, however, is incompatible with the previous API. All SlideBar-based Jetpacks must be updated, Mozilla said.

Also featured in version 0.3 is synchronous, persistent storage and a new storage API.  Jetpacks look better by default as well, Mozilla said. In addition, the upgrade simplifies text selection and enables users to get and set text from the system clipboard.