Twin directories of png:

[DIR]  ftp://ftp.mimuw.edu.pl/People/lewar/images/skanska_kasia/english/images/png/
[DIR]  ftp://ftp.mimuw.edu.pl/People/lewar/images/skanska_kasia/polish/images/png/
[DIR]  ftp://ftp.mimuw.edu.pl/People/lewar/images/skanska_kasia/polish/panel/png/
[DIR]  ftp://ftp.seul.org/pub/pingus/contrib/lawrence/lami.ovh.org/pingus/png/
[DIR]  ftp://82.96.64.7/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.eutelia.it/pub/Sunsite_Mirror/kernel.org/pub/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.uni-frankfurt.de/pub/Mirrors2/ftp.kernel.org/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.inf.utfsm.cl/pub/tex-archive/support/ghostscript/3rdparty/graphics/png/
[DIR]  ftp://ftp.inf.utfsm.cl/pub/tex-archive/graphics/metapost/contrib/macros/featpost/png/
[DIR]  ftp://ftp.psg.com/pub/modula-2/gpm/living/suburbs/images/png/
[DIR]  ftp://ftp.psg.com/pub/modula-2/gpm/living/suburbs/png/
[DIR]  ftp://debian.lcs.mit.edu/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.kfki.hu/pub/linux/ftp.kernel.org/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.internat.freebsd.org/pub/FreeBSD/ports/graphics/png/
[DIR]  ftp://ftp.cprm.net/.disk2/kernel/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.datacomm.ch/pub/mirror/ftp.kernel.org/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.kreonet.re.kr/tools/graphics/png/images/png/
[DIR]  ftp://ftp.kreonet.re.kr/tools/graphics/png/
[DIR]  ftp://ftp.kreonet.re.kr/CTAN/support/ghostscript/3rdparty/graphics/png/
[DIR]  ftp://ftp.kreonet.re.kr/CTAN/graphics/metapost/contrib/macros/featpost/png/
[DIR]  ftp://ftp.kreonet.re.kr/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/non-gnu/circus/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/non-gnu/grokedb/templates/binaries/images/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/non-gnu/grokedb/templates/images/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/gnu/3dldf/3dldf/manual/user_ref/3DLDF/graphics/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/gnu/3dldf/3dldf/manual/user_ref/graphics/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/gnu/3dldf/manual/user_ref/3DLDF/graphics/png/
[DIR]  ftp://ftp.kreonet.re.kr/gnu/ibiblio/www/savannah-checkouts/gnu/3dldf/manual/user_ref/graphics/png/
[DIR]  ftp://ftp.cs.helsinki.fi/pub/Software/Linux/Kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.prz.rzeszow.pl/pub/gentoo/portage/dev-ruby/png/
[DIR]  ftp://129.21.60.34/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.nz.debian.org/gentoo-x86-portage/dev-ruby/png/
[DIR]  ftp://ftp.cs.technion.ac.il/pub/misc/gip/incoming/promo/Rudzsky/gilad/all-files/StandardImages/png/
[DIR]  ftp://83.174.206.8/pub/soft/Messegers/MirandaMDpack/templates/svodka/teasers/png/
[DIR]  ftp://ftp.uni-hannover.de/pub/mirror/bsd/NetBSD/packages/current-src/pkgsrc/graphics/png/
[DIR]  ftp://ftp.uni-hannover.de/pub/mirror/bsd/FreeBSD/development/FreeBSD-CVS/ports/graphics/png/
[DIR]  ftp://ftp.port80.se/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.informatik.uni-oldenburg.de/pub/grafik/png/images/png/
[DIR]  ftp://ftp.informatik.uni-oldenburg.de/pub/grafik/png/
[DIR]  ftp://cdsarc.u-strasbg.fr/0/catj/J/A+A/481/123/png/
[DIR]  ftp://ftp.cc.keio.ac.jp/kernel.org/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.uni-koeln.de/tex/graphics/metapost/macros/featpost/png/
[DIR]  ftp://ftp.uni-koeln.de/graph/png/
[DIR]  ftp://130.251.19.2/pub/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.wh2.tu-dresden.de/pub/mirrors/latex/dante/support/ghostscript/3rdparty/graphics/png/
[DIR]  ftp://ftp.wh2.tu-dresden.de/pub/mirrors/latex/dante/graphics/metapost/contrib/macros/featpost/png/
[DIR]  ftp://ftp.wh2.tu-dresden.de/pub/mirrors/kernel.org/linux/kernel/people/mbligh/andrew/png/
[DIR]  ftp://ftp.wh2.tu-dresden.de/pub/mirrors/gentoo-portage/dev-ruby/png/
[DIR]  ftp://ftp.swin.edu.au/apache/incubator/sanselan/javadoc/org/apache/sanselan/formats/png/
[DIR]  ftp://ftp.swin.edu.au/apache/incubator/sanselan/0.97/javadoc/org/apache/sanselan/formats/png/