DMG2ISO is an Apple's compressed dmg to standard iso convert tool.
This tool handles z-lib compressed dmg images.

Usage:
 dmg2iso <image.dmg> <image.iso>

vu1tur <to()vu1tur.eu.org>

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                  947    2370  40.0% -lh5- c778 Jan 26 07:58 dmg2iso/base64.cc
[unknown]                  533     959  55.6% -lh5- 2f75 Sep 26  2005 dmg2iso/base64.h
[unknown]                  857    1660  51.6% -lh5- bd33 Jan 26 08:00 dmg2iso/base64.o
[unknown]                 7016   18011  39.0% -lh5- 85dd May  5  2005 dmg2iso/COPYING
[unknown]                25073   44292  56.6% -lh5- aa31 Jan 26 08:12 dmg2iso/dmg2iso
[unknown]                 2564    8595  29.8% -lh5- a364 Feb  2  2006 dmg2iso/dmg2iso.cc
[unknown]                  779    1521  51.2% -lh5- 6aed Jan 26 08:10 dmg2iso/dmg2iso.h
[unknown]                 3399    7136  47.6% -lh5- 35ba Jan 26 08:11 dmg2iso/dmg2iso.o
[unknown]                  257     412  62.4% -lh5- 9bb9 Jan 26 08:17 dmg2iso/dmg2iso.readme
[unknown]                 3048    9544  31.9% -lh5- 6ea0 Dec 27  2006 dmg2iso/include/zconf.h
[unknown]                20052   66188  30.3% -lh5- 6547 Dec 27  2006 dmg2iso/include/zlib.h
[unknown]                43590   90322  48.3% -lh5- 0706 Dec 27  2006 dmg2iso/lib/libz.a
[unknown]                  245     622  39.4% -lh5- 024e Jan 26 08:12 dmg2iso/Makefile
[unknown]                  158     218  72.5% -lh5- 54c3 Jan 26 08:15 dmg2iso/README
[unknown]                  126     253  49.8% -lh5- 324d Dec 28  2006 dmg2iso/Readme_zlib
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total        15 files  108644  252103  43.1%            Jan 26 20:23