System tray or other background access mechanism

At some point I'm looking to write a game that won't require constant activity and so it would be useful to have some kind of background access mechanism for it.

Not sure how doable this would be. Of course Windows has the system tray for such options, but not sure what Linux/Apple has up its sleeves.

If it is a possibility then that's great. Otherwise it would be interesting to explore alternative ways of creating the same effect.