Three arrows show the percentage of memory used for programs and system,
memory used for cache and swap space. I have written asmem to be swallowed
by the AfterStep wharf module, but it can be used with everything else too.

Building:

Type xmkmf to create the makefile and make or make install as root. 
The installation requires only the binary itself which becomes
/usr/X11R6/bin/asmem by default.

The following command line options are supported:

  -e  <command>         Run /bin/sh -c with the specified command 
                        on a mouseclick in the window.
  -i                    Start as an icon
  -w                    Withdrawn option
  -p  [+|-]<x>[+|-]<y>  X and Y position of the window after
                        start
  -bg <color>           Background color. The default is black.
  -fg <color>           Foreground color. The default is LightGrey.
  -a1                   Color of the upper (memory) arrow. Default 
                        is green.
  -a2                   Color of the middle (cache) arrow. Default
                        is yellow.
  -a3                   Color of the bottom (swap) arrow. Default
                        is red. 

An entry for AfterStep .steprc could look like this:

*Wharf asmem nil MaxSwallow "asmem" asmem -e 'application to execute on click' &