X11 on Mac

change font of xterm, by customize the xterm command

xterm -fa Monaco -fs 10

xterm -fa "Andale mono" -fs 10

change fullscreen background of X11 on Mac OS X, write in your ~/.xinitrc file:
```
/usr/X11R6/bin/xsetroot -solid black &
exec quartz-wm
```
reference: http://forums.macosxhints.com/showthread.php?t=32760