I use xchat for irc, and by default, xchat doesn't show pop-up notifications (unlike growl in Mac, which shows pop-up notifications) whenever something is posted on the message box. Is there a way to show these notifications, or is it not possible at all?
Are you using xchat or xchat-gnome? If you are using xchat-gnome then you should get on screen notifications. You can check by going to Edit > Preferences > Scripts and Plugins > and checking that the "On-screen display" plugin is there and enabled.
Here is how it make it work for me: http://roman-ivanov.blogspot.com/2013/03/xchat-integration-with-unity.html , but it started blinking, do not find way to make notification balloons with message.