Mozilla Labs has unveiled a platform called Jetpack aimed at enhancing the already huge library of extensions and add-ons available for the Firefox web browser.

Jetpack is still in its early phase, but provides an application programming interface (API) for developers to create add-ons using just web languages such as HTML, CSS and JavaScript.

"The add-ons community for Firefox is arguably one of the largest and most vibrant sources of innovation on the web today," said Aza Raskin, a member of the Mozilla Labs team, in a blog post.

"However, we have only scratched the surface of its potential. Jetpack explores new ways to extend and personalise the web. It's an API which allows you to write Firefox add-ons using the web technologies that you already know."

Mozilla is hoping that the openness of Jetpack will help to swell its already formidable collection of 8,000 developers, thereby expanding and enhancing the more than 12,000 existing add-ons.

Raskin warned that Jetpack is a very early 0.1 release, however, and is " unpolished, unfinished and still highly prototyped".

"We are planning on entirely revamping things for the next iterations within the coming days and weeks. We need your feedback, both on the particulars as well as the direction. In particular, we are actively seeking feedback on the API design," he wrote.

Jetpack will give developers API support for status bars, tabs, content scripts, animations, external API libraries such as Twitter, inline debugging with Firebug and a host of other development features.

From a user perspective, the platform will allow new features to be added to the browser without the need to restart the application or the computer.

Jetpack is currently just for testing, development and feedback, and the API does not include a fully formed security model.