A notification system you control... Applications register notifications but ultimately you decide which notifications should appear - and how they appear. All of this is centralised into a single location - Snarl's preferences - so you know where to look each time, no matter which application it is. You can also assign different styles and schemes to each notification. Extensible... Support for applications can also be added through a feature unique to Snarl: extensions. These are small modules which run in the same process space as Snarl and allow Snarl to detect events occuring in other applications.