How do I run a GUI app via SSH? I'm used to working on Unix/Linux and recently moved to Mac. In used to be able to do this:
derick@linux1:~$ ssh -X linux2
derick@linux2's password:
derick@linux2:~$ xclock

I've install X11 from maxports and I can do the same from my mac. If I try the reverse by ssh-ing into my mac from linux I can only run certain apps:

/usr/X11/bin/xclock works fine

Something like /Applications/Preview.app/Contents/MacOS/Preview opens the GUI on the mac.
It seems that this is not possible on a mac? If not, how do I run an application remotely (on a mac) with a local (linux) display? Do I need some third-party app?


Update:
To be more precise: I have synergy and use Mac for coding. On my linux PC I would like to see another application's display (GUI) from Mac. Thus, 'live screen sharing' apps like VNC will not work.
For example I'm working on my mac in app A (say Word) and want to see the output of Excel (running on mac) on my linux PC next to me. (Simulating a dual screen via the network). It worked nicely on linux, hoping for a solution for mac.
The Mac OS X native application do not use the X protocol for the rendering, but the Mac specific protocol. So you cannot use ssh X protocol forwarding as you could with a Linux workstation.

As you discovered, the reverse is not true, you can install an X server on Mac OS X and have the Linux program appear on your Mac.

What you can do is use either Mac own desktop sharing facility or install a VNC server. Then from your Linux box, you connect to your Mac through VNC instead of ssh.