This just caught be by surprise. After the recent upgrade to Mountain Lion
I tried to install DB2 on one new machine and couldn’t get the graphical
installer to work. I kept getting errors that the DISPLAY variable wasn’t set
which sent me searching for causes since I usually do that automatically
when logging into a machine with ssh (ssh -X user@host).
As it turns out, Apple decided to turn over the development to the XQuartz
project to keep up with X11 development. If you need X11 on your Mac,
here’s where to find it: