From: Steve Linton <sal@dcs.st-and.ac.uk>

The problem is that, last time we explored this, many Windows and
Mac users did
not reliably have reliable tools to unpack gzipped tar archives, while we have
a single source file that provides everyone with unzoo at the cost
of one extra
step. Also, since we control the unpacker, we have added a few non-standard
features, to allow, for instance, automatic correct handling of text
and binary
files under Windows or MacOS. The compression is not as good as more modern
systems like gzip or bzip2, but the difference is not huge, and the people to
whom it mostly matters (modem users) probably recover some of the extra
compression in their modem hardware.

From: Dmitrii Pasechnik <d.pasechnik@twi.tudelft.nl>
I don't know about MacOS, but WinZip 7.0 (downloadable Win32 program,
see http://www.winzip.com) unpacks *.tar.gz (or *.tar.Z, or *.tgz)
files just fine;
moreover, it performs the binary/text conversions, just as unzoo.exe
that GAP download site provides.
(And WinZip does not use any external programs for this, either).

There are absolutely no problem for the Mac. Everybody nowadays makes use
of StuffIt Expander which does the job perfectly. I don't see any benefit
in using zoo nowadays. For a Mac user, it takes much longer to extract a
zoo archive than any other archive downloaded from the web.

I don't think the change would be very long to implement, since I
guess a shell script would do the job easily. It would probably be
nothing to do compared to the amount of work that represents GAP !

Jean-Eric Pin