We are Project-10 and we have extended Snarl, the notification service for Squeak, as part of the software engineering lecture at Hasso-Plattner-Intitute.
Now it's possible to display the notifications outside of Squeak - have fun!

(1)  Get the git-repository.
(2)  In Squeak, add a new filetree-repository and choose the folder 'packages'.
(3)  Open the repository and install the packages in this order:

           ... on MacOs and Windows
              (1)  FFI-Pools
              (2)  FFI-Kernel
              (3)  Project-10

           ... on Ubuntu
              (1)  install Libnotify *
              (2)  install the Squeak-Plugin CommandShell from SqueakSource **
              (3)  Project-10

If you want to test the internal function of Snarl also load Project-10-Tests.

* for Ubuntu with 'sudo apt-get install libnotify-bin'
** http://www.squeaksource.com/CommandShell.html

After installing, check Snarl's class documentation to learn how to use it.

If you want to develop and improve our Snarl, we created some issues which we considered useful as some suggestions.