On my Debian GNU/Linux (-unstable) box, I have X.org + GNOME + openssh-server installed. I would like a friend, using Windows XP, having a shell account on my computer to be able to use the GUI on my computer .. something like .. PuTTY but graphical rather than .. errh .. command line only.

In my /etc/ssh/sshd.conf I have the following:

(is this all I need for this thing to work?)

What client(s) does my friend need for this type of conenction?

If your friend is using Windows, then your friend will need a kind of "X compatibility layer" in order to use the X11 forwarding. Linux handles X11 forwarding naturally, but Windows doesn't know what to do with the stuff that's coming, so you'll need to install somekind of thing on it. I know there are at least two "good" choices to pick up, and at least the other one of them is commercial; I don't know any 'free of charge' versions. No idea if you could use cygwin to install X on top of your Windows and so on, but you might have to do some work to get it going...

I'd rather ask if your friend was ready to move to Linux, it's probably easier than trying to get Windows work

EDIT: also, after this your friend will only get an ssh connection, from which s/he'll be able to launch applications that will be shown on her/his desktop. To get a complete desktop shown on top of the Windows one, you'll need something bigger, a "Remote Desktop Connection". But that's another story..X11 forwarding via ssh is easier, and works probably better especially if you don't have a very fast connection.

That's what I need, where do I find documentation on the subject?