[Interest] Singleton application

[Hamish Moffatt]

Is there any support built-in for making an application a singleton (ie 
you can't launch multiple instances), or does anyone have a recipe?

I'd actually like a second launch to signal the first, passing on any 
parameters, much like the web browsers do. (eg link clicked from an 
application creates new tab in existing browser instance.).

I need this to work on Windows and Mac.


Hamish