growl: Growl osd.basic translator
This gateway listens for osd.basic schema xPL messages. Upon receipt of a write command, the contents of the text item from the osd.basic message will be sent as a broadcast to all Growl listeners.

Configuration is straight forward. There are three fields.
appname: set the application name that Growl will identify that the messages are from.
notename: notification name. It isn't clear it matters what this is set to.
password: if your Growl listeners require a password, set it here.