OS X Terminal/X11 xterm Focus

For those who have jumped to Mac OS X from a Unix-type environment (Solaris, Linux, AIX, etc.), OS X has an X11 window manager as part of the core OS. This allows you both access to the command-line of the powerful OS X operating system and remote-display of applications from other Unix-type machines.

One thing is missing (by default) that I've missed, until now: focus-follows-mouse. For those that don't know, this changes the window focus under X11 (or the Terminal application) when you move your mouse over the window. No need to click on the window to cause the focus to change to that window. This is especially handy when copying-and-pasting between windows.

So, here goes. To change the X11 xterm and Terminal default behavior to focus-follows-mouse, go to an xterm or the Terminal app and type:

defaults write com.apple.x11 wm_ffm true
defaults write com.apple.Terminal FocusFollowsMouse -string YES

To change them back to the default, simply type:

defaults write com.apple.x11 wm_ffm false
defaults write com.apple.Terminal FocusFollowsMouse -string NO

Or, you can delete the preferences completely (if you're paranoid) by typing:

defaults delete com.apple.x11 wm_ffm
defaults delete com.apple.Terminal FocusFollowsMouse

Hope that helps someone out there!