Wojciech Puchar writes:

>> You may want to use a small window manager like blackbox.
>does it consume less than fvwm2 (minimally configured!)?

fvwm 1.24r is probably the best of the well known ones for small boxen
with tight memory and slow cpus (if you don't load the extra fvwm modules
like goodstuff etc., of course.)
it consumes significantly less memory than even twm and is about half
the size of fvwm 2.x.  it also doesn't paint gradients and stuff with
hundreds of colors like blackbox, which puts extra load on the X server
and eats up server memory and is slow on screen updates, or displays
everything with pixmaps stored in the server, like most window managers
with "themes" have to do in order to achieve their highly configurable
look&feel.
if you're really tight and the machine is paging all the time, you might
try more minimal ones like 9wm, which trade almost all features except
the very essential ones for small program sizes.

--mkb