Back in October, Mozilla released Firefox beta 17. This particular version of the eight-year-old browser brought with it the Social API - a new tool that would allow developers to integrate social networks right into the browser experience. Facebook was the first partner to use the Social API, and now it's available to all.
Mozilla announced that Firefox 17 is now available, and the Social API is out of beta. Now everybody who uses Firefox can have Facebook messenger integrated directly into Firefox with the social API. It's just a simple matter of turning it on, and Firefox users can then enjoy being constantly spammed by their Facebook friends all the time.
Aside from chatting with friends, the Facebook for Firefox sidebar also sends you notifications. The usefulness may be overstated as many people, like yours truly, uses their smartphone to check notifications. Most would probably still use a smartphone to check Facebook versus a desktop browser, but it's a nice gesture nonetheless.
Now, Facebook is the first partner to use the Social API, but it's open for all developers to play around with. It won't be long before we start to see the likes of Twitter, Google+ and other services built right into browsers. Mozilla and Google also share APIs a lot so it wouldn't be that much of a stretch to see this kind of stuff coming to Chrome sooner than later.
If you already have Firefox, it should have updated by itself by now. If you moved away but want to try the new Social API, you can get Firefox here. After that, you can turn on Facebook Messenger for Firefox here.