The iMac and HP Z1 have a bi-directional DisplayPort/Thunderbolt port, which lets them be used as a Display for another computer. Apple calls it Target Display Mode, though HP doesn't seem to have a special name for it. This is really quite useful, I've used an iMac hooked up to a Linux machine at a previous job, and it's awesome to switch between the two machines when you've only got space for one display on the desk. The feature is invoked by a fairly non-standard keyboard combination. Here is a video illustrating what I mean (http://www.youtube.com/watch?feature=player_detailpage&v=Y7_OZgBX8kQ#t=60), note how he switches the iMac from being the display for the MacBook to being an iMac again via keyboard shortcut (sort of off-screen).

However, this feature is only implemented in OS X and Windows (via HP's My Display application) on the iMac and Z1 respectively. Which means that if, for example, a Z1 has Linux as the primary OS, the Z1 cannot currently be used as a monitor for a laptop or another computer (via Target Display Mode). As far as I've been able to discover, Target Display Mode does not exist under any flavor of Linux.

What would it take to support this in Fedora? Is this a Desktop-centric feature for Gnome/KDE/Cinnamon, or is this something that would/should be part of the Linux kernel itself? I don't think it's directly part of a graphics driver (at least on Windows, since HP released My Display as a separate program), but again I'm not sure. 

I'd love to have Target Display Mode, but before submitting a feature requesting, I wanted to better understand the implications - and see if perhaps I'd missed something. If it can/should be done as a stand-alone program, that'd be great to know too.

Thanks!

Chris