Jetpack is Mozilla’s new API for developers to create add-ons for the Firefox Web browser. Currently, many Firefox add-ons work through an extension called “Greasemonkey,” which some fear may disappear if Jetpack takes off. Jetpack, however, has its advantages in terms of compatibility and the ability to activate new features without a browser restart. It allows developers to create adds-ons using web technologies including HTML, CSS and JavaScript.

Jetpack is an open source application programming interface (API) that will let users create add-ons for Mozilla’s Firefox browser using the Web technologies they already know.

Meanwhile, some developers are concerned that the launch of Jetpack could mean Mozilla will kill off Greasemonkey, a Firefox extension that lets users customize the way Web pages look and feel.

“How is this any different from Greasemonkey?” asked Casey in a comment on the Mozilla Jetpack blog. “Aren’t you just risking taking development resources away from them and their community when they already have something great in place?”

Greasemonkey is not a Mozilla project, Raskin pointed out. However, there is no conflict between Greasemonkey and Jetpack.

“Greasemonkey is an awesome Firefox extension,” Raskin said, “but it’s about modifying pages you’re looking at, whereas Jetpack lets you modify the browser.”

With 12,000+ add-ons, it’s no wonder Firefox draws a lot of users’, and by turning to web technologies, Mozilla is hoping to pave the path for more developers to create add-ons.

“We want to grow our community of developers by orders of magnitude through making add-on creation much more accessible, and yet more powerful by developing it as an extensible platform for innovation itself. Many useful Jetpack Feature’s can be written in under a dozen lines of code,” says Mozilla developer Aza Raskin on the company blog.

“Jetpack will be an exploration in using web technologies to enhance the browser with the goal of allowing anyone who can build a website to participate in making the web a better place to work, communicate and play.”

There’s already a few sample add-ons created in Jetpack to play with, including a simple ad blocker program and Gmail notification extension.

More about Jetpack

Jetpack is an exploration in using Web technologies such as HTML, CSS and JavaScript to create add-ons for the Firefox browser, according to Mozilla.

It will let users add new features without having to worry about compatibility and without having to restart their browsers, as is now the case.

“Jetpack is an open source platform on top of which anybody that can write a Web page can now enhance the browser,” Asa Raskin, head of user experience at Mozilla Labs, told LinuxInsider. “We want to make the Web better and make it as personal as it can be.”

The current Jetpack release version is 0.1, which means it needs a lot more work. Mozilla intends to tweak and fine-tune the project with feedback from developers, especially on the API design.

“We ask ourselves, what are the cool innovations we can’t see around the corner that are coming, because all of a sudden there are new communities — students, anyone who can create a Web page — that are making the open Web a better space,” Raskin said.