I started writing this in the Fedora forum but decided it might fit better in the Newbie forum...

I just did a "minimal" install of FC3 on a box that will be used as a home server. It has no screen (except one temporarily connected during install) and I SSH in from my RH9 desktop. X is not installed on it.

The thing is, I thought that some GUI programs would still work over SSH? They did on my previous FC2 installation. E.g. when typing emacs in my SSH window, the X version would automatically appear on my RH9 box. Now it does not. And the programs I was really trying to use (emacs was an additional test), like system-config-users will not run because they "require a running X server" On my previous install, I did not choose minimal, I manually deselected pretty much everything I did not want. I suppose it is quite possible some X things were automatically installed because I chose programs that required them.

Anyway, I guess my real question is: Do I need to run X on the server to use GUI tools remotely?

yep

Ouch, to think that I ran a server for several months without knowing that it was running X...

You do not need it running on the server to start a X app from a remote location. You may need X installed but not running I can't remember right off hand I will check and get back. Make sure when you connect to the server that you tell it to forward X connections
"ssh -X nobody@server" you can set this in ssh_config so you don't have to manually tell it.

Yep. X needs to be installed but not running.

Chances are it wasn't running. X is really only bad if it is listening for incoming connections( tcp port 6000), or if alot of untrusted people have physical access. I always install it on my servers but don't start it.

OK then, hopefully, I wasn't running it after all At least I know it was not accepting remote connections (except over SSH, as mentioned before). Only port 22 was open to the outside world and even on that only a few hosts were allowed to connect.