How to display a notification even when a full-screen application is currently running?

My program needs to display a notification once in a predetermined interval. Under Windows, Shell_NotifyIcon does the job开发者_运维技巧 well except that when the user is running a full-screen application, the notification isn't shown. Though that may be the right thing in most of the cases, in my case I need to ensure the notification can be seen even when the user runs a program in full-screen mode (such as a video game), but without causing the full-screen application to be minimized or otherwise intervening with the user playing the game. Much like what Skype does when a message is received. How to accomplish that?

Platforms: Windows, Mac OS X

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in gnu linux where is libnotify or just notification daemon, there might be ported version of it to one of your platforms, have look.

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Take a look at Growl - it's a popularly supported third-party notification system (that hands control of how the user wants notifications displayed to the user) - I know it is used by Skype for notifying receipt of messages if it is installed.

What I am not sure is whether it is the sole notification system used by Skype.