Facebook Messenger for Firefox arrives in finished form, keeps us in the loop without an extra tab

Mozilla kicked off the fall with beta Facebook Messenger support for Firefox that flexed the muscle of its Social API. Now that the snowfall is here in earnest, so too is a polished version of the conversation-driven add-on. Those running the latest version of the browser now just have to enable Messenger for Firefox from its Facebook page, at which point it's an always-on (if thankfully optional) companion to any web explorations: along with keeping chats alive without an extra tab, the resulting sidebar will ping for less urgent events such as post comments or photo tags.

[Source: Engadget]