Mozilla Labs Unveils Jetpack API

Mozilla Labs' virtual lab development team has announced the debut of Jetpack, a newly formed browser enhancer using open Web technologies.

The API allows users to write Firefox add-ons. The launch site notes the project includes pre-release software that is still being actively designed and developed, and is being made available for developers and testers only.

The site also contains a list of guiding principles for what Mozilla Labs calls an "experiment," including a foundation solely Web-based (HTML, JavaScript and CSS will be the only tools required), and the ability to debug the browser without restarting using common Web development tools like Firebug.

The lab puts a strong focus on the "develop once, run anywhere" guideline, noting add-ons should be able to run in Firefox Mobile, Thunderbird and "anywhere else." Mozilla states developers shouldn't have to worry about some internal change in Firefox breaking extensions. "Add-ons will work through a version'ed facade-pattern so that you won't be in a constant struggle to keep your extension working with the latest FF edition," the lab points out.

Security is also one of the four main headings for guiding principles; Jetpack is designed to provide access to only the privileges needed, with security issues always presented in social terms, not technical terms. "Short and easy to review code ensures that potential security issues are shallow, and review times short," reads a blog post by Aza Raskin, Atul Varma and Nick Nguyen from the Jetpack development team.

Mozilla also wants to keep Jetpack extensible with architecture that will allow for the easy inclusion of reviewed and versioned third-party tool kits like jQuery or Dojo and API libraries like Twitter, Delicious or Google Maps. Also included on the site are two demonstrations, one for an e-mail notifier and the UnAd content filter demo, which demonstrates in about 80 lines of code how to build a Jetpack feature that can remove unwanted scripts, images and iframes with a "pretty UI" for turning the feature on and off.

Several other demonstrations can also be viewed, though the majority are notifiers of a kind. Mozilla Labs is also taking great care to alert programmers to the potential dangers of third-party Jetpack features. "The features referenced here have not been reviewed by Mozilla," a warning on the page states. "They may contain malicious code, so use them only at your own risk."

The three Labs members also encourage programmers to join the project. "Mozilla Labs is a virtual lab where people come together online to create, experiment and play with Web innovations for the public benefit. The Jetpack experiment is still in its infancy and just getting started," they wrote. "As with all Labs experiments, Jetpack is an open source project and everyone is welcome to participate in its design, development and testing."