Why not take a look at another secure browser that meets commonly used standards and is running on any operating system?
This screenlet for GNOME and XFCE desktop environments displays upcoming events using the Google Calendar. For notifications the notification library of Python is used.
At the moment I am quite satisfied with the screenlet. There are some issues of the screenlet daemon reading from the GNOME keyring, but this is a different story. The only thing missing I can think of are error/warning messages.