Mozilla and Facebook today announced the official launch of Facebook Messenger for Firefox. While the new addition became available last month with the release of Firefox 17, Mozilla is officially flipping the launch switch today.

Facebook Messenger for Firefox is built on Mozilla’s Social API for the Web. The new feature allows Firefox users to chat away with their Facebook friends no matter what site they’re on; as my colleague Ken Yeung put it, “you could be on Twitter and still send Facebook messages.”

To use the feature, you’ll need to install Firefox 17, visit the Facebook Messenger for Firefox page and click the green “Turn On.” Once you enable it, you’ll get a social sidebar with your Facebook Chat, updates like new comments and photo tags, as well as notifications for messages, friend requests, and so on that you can respond to directly from Firefox.

fb messenger firefox 730x511 Mozilla launches Facebook Messenger for Firefox, lets you IM your friends from anywhere on the Web

Facebook Messenger for Firefox is part of a unique partnership between Facebook and Mozilla, which hints that the two could bring even more Facebook features to Firefox in the future. Mozilla is the one that reached out to Facebook earlier this year about the project, which is dependent on ” on a number of HTML5 standards, such as WebSockets and Shared Worker,” according to Facebook.

Mozilla’s justification for the feature is that as social sites become more and more prevalent, the organization wants to make it easier to access them. Here’s the vision:

Mozilla is a non-profit organization with a mission to promote openness, innovation and opportunity on the Web and we can’t wait to see what cool Web experiences developers will build on our Social API. We want to build a social standard for the Web to give developers more opportunities and users more choice, much like we did with our work on OpenSearch. Imagine using the Firefox sidebar, toolbar buttons and even an AwesomeBar button for news, music, finances, email, group projects and more.

In other words, this isn’t going to stop at Facebook; as we’ve noted, Mozilla has integrated a whole Social API into Firefox. In fact, the company says it will “soon add support for more features and multiple providers.” Is Twitter next?

Image credit: Gabriella Fabbri