I finally upgraded my MacBook Pro to Leopard in preparation for the bar exam. I was pretty happy with Tiger and saw no real advantages in Leopard, so I wasn't in a hurry to upgrade. However, I wanted a fresh Boot Camp install of XP for the bar exam, and that required the upgrade, because the Tiger Boot Camp never left beta and had expired.

So, over the last week, I started noticing X11 running, even though I hadn't been running X11 apps. That struck me as odd and just a bit scary. I started hunting for some virus or trojan to no avail.

Apple added dynamic X11 support to Leopard through launchd. So, every time I cranked up an SSH session, X11 was being launched. Apparently, I asked for this behavior:

gregory-haverkamps-computer:~ gregh$ cat ~/.ssh/config
ForwardX11 yes
#ForwardX11Trusted yes

I don't remember setting that, but since the timestamp of the file dates to 2005, it's no surprise I'd forget. Normally, it's not an issue, because I don't have a display set, anyway.

So, I just need to disable automatic X11 forwarding (or execute ssh -x) to solve my problem. And finally, I can stop worrying about something going nuts on the machine.