Mozilla is rolling out Firefox 41 to desktop and Android users and says it's now the first browser to have built-in instant messaging. That feature only works on the desktop version for now, but lets you IM directly from a Hello video call whether you're on Windows, Mac or Linux. Because Hello is WebRTC powered, you can chat with Chrome or Opera users once it's supported on those browsers. If you happen to use Firefox's chat (which Mozilla co-developed with Telefonica) instead of say, Skype, it could come in handy if you're traveling and using an internet cafe.
Source: Mozilla