With KDE4 you can disable background services, Desktop Effects and
all goodies in ``System Settings''. Then It uses 500MB here in
average, and not much CPU with Desktop Effects disabled. With some of
the goodies it uses 600MB here, not that much. Also Phonon does not
require PulseAudio at all, and can talk to ALSA very smoothly.
I wonder if it would be possible to have a JACK backend for
KDE/Phonon... That would make a nice environment for pro audio work
with a ready-made fancy desktop.
I like OpenBox a lot too. I used it a lot. Xmonad is also great, if
you enjoy tiling WM.
The downside for OpenBox (not xmonad) is that it seems not very
actively developed in the last year or so, not much releases or even
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