I seek a X software to connect my pc to Unix with the unix GUI.

VNC - free but slow makes screenshots of your desktop to send it over the wire http://www.uk.research.att.com/vnc/ , Xwin32 - commercial http://www.starnet.com/products/ , and search here on forums I remember acid_kewpie suggested another free alternative close to Xwin.

Strictly speaking VNC is not remote X, its remote desktop using its own protocol, and it has been ported to many systems, including handhelds!

I've been using VNC on my local network (10MHz ethernet) and its acceptable with linux server and windows client or vice-versa. The only thing to note is that it will try to compress the colour map which is not a problem if you aren't going to be viewing images over a vnc connection. For some reason the client implementations I've tried on Mac OS X have been slow, also there is a "portable" java client but that is really slow, this will even work as an applet but I've never gotten the vnc in built webserver to work.

It is a bit different from other systems in that the virtual desktop will be as you left it even when you move between client machines or simply power cycle your client pc. This means you can leave stuff running on unix and it'll still be there until you kill off that vncserver.

Best of all its free

yeah i'm using VNC at the moment for a linux-linux desktop. it's really handy actually as i have gtk-gnutella running 24-7 on my server and i can then just instantly pull it up on either my nix workstatino or my girls windwos machine, and then just close it again. you can't really have that flexibilty with a proper server like Xwin32.

oh and it would seem that XwinX was abandoned over a year ago