Desktop Notifications are new in Mibbit and they only work in Google Chrome and Safari. It might also work in other browsers which use the WebKit engine. It uses a currently nonstandard feature built into Webkit browsers.
Notifications are a way for your applications to provide you with new information (chat in channels or PM), without you having to switch from the application you're already in.
How it works
You have to enable them in your preferences in the General tab under Alerts. After you have ticked the select box the browser will ask your permission to show alerts on the desktop. Don't forget to hit the save and close button or else it will not work. The notifications will show you the amount of new lines in a certain channel when your Mibbit window is not focused. See also http://blog.mibbit.com/?p=881
This feature is new so it might contain bugs and might not be fully functional at some points. Feel free to report bugs or suggestions to our staff in #help