I've just purchased MatLab, which requires X11 to run, and which I don't currently have installed on my PowerBook (running OSX 10.4.4). The message during the installation of MatLab said this can be installed from the OSX Installer disk. Unfortunately, I'm at university and won't be going home for another month, and my installer DVD is at home! Is there any way I can install X11 without the installer DVD? Also, what is X11, just out of interest?