xterm

Turn off X11's xterm sounds

Snippet

Turn off xterm's terminal bell so that backspace on an empty line doesn't DING DING DING (and so that I can have the sound up on my laptop, yay!)

xset b off

Change xterm font and colors on the fly

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Sometimes you want a new xterm window with smaller fonts.

Current .Xdefaults

xterm*Background:               black
xterm*Foreground:               LightGreen
xterm*cursorColor:              LightBlue
#xterm*pointerShape:             arrow
#xterm*pointerColor:             blue
xterm*pointerColor:             white
xterm*font:                     *-fixed-*-*-*-18-*

You can, however, include the values on the command line, too. This one is a legible size, if tiny:

xterm -fa monaco -fs 9 -bg black -fg LightGreen &