Thanks to helpful folks on usenet, who seem amused that Maccies are starting to ask such basic questions, here is how to run ifeffit from terminal.app:

: Wow, this sounds close to a solution to something I've been puzzling : over. I have Xwindows installed and I can use pgplot from an xterm : running under XDarwin, but I can NOT run pgplot from Terminal.app. If I : try I get a message: : PGPLOT /xw: cannot connect to X server : I tried putting the DISPLAY=:0.0 export DISPLAY into .xinitrc and : .cshrc, to no avail. Basically, I don't know what I'm doing here :) and : I am just blundering about.

That command is for sh/bash, not tcsh. For tcsh, you want setenv DISPLAY :0.0

If you're going to put it in your .cshrc file, then use if( ! $?DISPLAY ) setenv DISPLAY :0.0 so it won't override DISPLAY if it's already set, such as by a forwarded X11 connection.

There were several interesting replies, one of which was basically, "I know how to fix it, but I refuse to use c shells". What's -that- about?