Note: ScreenRecycler is no longer under development, and it is no longer available for sale.ScreenRecycler allows you to use your other computer as a second monitor.
Many Mac users have a second computer sitting right next to their main computer on their desk including a nice display. ScreenRecycler now enables you to use this spare computer as second display for your Mac. You can even use an idle machine for that purpose.
It's like a dual monitor setup without the need to buy an additional monitor. Just start ScreenRecycler on your Mac then connect to ScreenRecycler via VNC from your second machine.
Recycle your old Mac and Windows machines !