X11
What is X11?
These days, X11 is not hard to install. But what is X11 exactly? X11 is a windowing system for UNIX, and very rudimentary at that. The idea is that a unix application can communicate to the window “server” and say “draw a window” or “draw a line” or very basic commands like that. And then, X11 draws whatever it’s told. In order to make X11 have some sense, a program called a “window manager” keeps tabs on all the various windows that have been drawn. The Window manager gives the X11 it’s feel.
Installing X11 and Apple’s Windows Manager
Installing X11 is easy. It’s in the optional installs section of the Tiger DVD, and on it’s on Panther CD #3 in the “Packages” folder called X11user.pkg. Here are some Tiger screenshots.
Once X11 is installed, it’s place in /Application/Utilities. From there you can run it with a double click. Apple has a nice Aqua based windows manager that runs by default. It will run “rootless” meaning you can see your other OS X applications, and X11 windows can be minimized, etc.
Personally, I prefer to run full screen and use a different windows manager - the enlightenment - which has multiple desktop and workspaces and which I install via fink. If you want to run a different window manager you have to create a .xinitrc file in your home directory. It’s best to start with Apple’s default one and make changes…
% cp /private/etc/X11/xinit/xinitrc ~/.xinitrc
The .xinitrc file contains a few commands that get X11 going including running the window manager.
When you run IRAF or IDL you’ll want to launch them from within an X11 xterm or xgterm window. Don’t type cl or idl in a OS X Terminal window if you want any graphics to be drawn. That won’t work. You must be running X11 when you type those commands, you must be in some kind of X11 based terminal - xterm, rxvt, xgterm. X11 should appear in the top left of the screen next to the Apple menu.
Now that you have X11, you can install X11IRAF.