Using another Mac as a display My MacBook Pro (OS X 10.8) only has one port for an additional monitor but I want to add a third monitor. I have a spare Mac mini (OS X 10.5) and I want to use it to support a third monitor. Is there an app that will use another Mac as an extended desktop?

If one does not exist then I would like to know what frameworks and libraries I would use to write an app for both the Mac mini and the MacBook Pro? How would I write the drivers? I intend on connecting the computers using FireWire. I have been learning how to write Cocoa applications.
Yep, there's an app for that.. (or two)


"ScreenRecycler" http://www.screenrecycler.com/ScreenRecycler.html
"AirDisplay" http://avatron.com/apps/air-display


I have used it, it works, but it's much better over an Ethernet connection instead of WiFi just be forewarned.

Also, you could use a (~$50) USB -> DVI adapter with the DisplayLink software for Mac and just add the monitor to your computer via USB, but honestly the performance is going to be about the same as AirDisplay over Ethernet (you just wouldn't have to run the other computer)

Anyway I have used both methods and found them to be very useable for mostly text-based work as a secondary screen.