I added AIF support to sfubar, and it is able to add loop points to AIF
files.  I have tested it on NetBSD/i386, NetBSD/sparc64, and Windows XP
Pro.  I put the source code in the public domain.

It can be fetched at one of the following:
http://terrorpin.net/~ben/docs/alt/music/soundfont/sfubar-3.tgz
http://terrorpin.net/~ben/docs/alt/music/soundfont/sfubar-3.zip

Cheers,

Ben

p.s.

My remaining problem is figuring out how to get csound4 to continue
through a wavetable after ending the sustain loop.  Csound seems to
abruptly cut off at the end of the sustain loop.