W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > January to March 2002

Re: access to plug-ins

From: David Woolley <david@djwhome.demon.co.uk>
Date: Thu, 24 Jan 2002 20:40:44 +0000 (GMT)
Message-Id: <200201242040.g0OKeis15915@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org
> plug-in/application such as WinZip or any other tool that is not
> involved in multimedia?

Note that WinZip is not free, in a money sense, software.  There
are free command line tools for handling modern ("flate" compression)
.zip files.  .zip actually originated with pkzip (not free).  Your
assumption of WinZip shows how Windows has dominated everything.

I would be tempted to to generalise the GPL rule on distribution
media.  They say that the source code must be provided on media
customarily used for the distribution of source code.  I would
say that if .zip files are the customary format for distributing the
resource in question, then you don't need to provide a tool.  If
that is not the case, why are you using the format?  Note that
HTTP/1.1 supports the use of same compression algorithm used in 
modern .zip files on the actual HTTP data stream.

Note that zip is not a standard format for Unix, although the free
implementation will run on it.  Best practice for Unix files that are
not OS specific is to use .tar.gz.  If the files are equally relevant
to Microsoft users, a site will also include .zip files.  If they are
being really good, and the files are relevant to the Macintosh, they will
also provide stuffit files (source code for Macs is relatively rare as
it was not marketed as a user programmed system).  Commercial Unices
generally don't have gzip as standard, but free software users are
likely to have it; if you are targetting something other than open source
software at users of commercial Unices, you need to use .tar.Z as your
lowest common denominator.

Note that .zip is quite often used with no advantage, except possibly
to fool firewalls, and web servers that haven't had their MIME
Types configured properly.  People don't seem to realise that PDF is
compressed already and will zip a single PDF file; this is something that
particularly annoys me, as it converts a resource that can be viewed
directly (and even incrementally) into one that needs to be downloaded
and then extracted.  There is some gain, but it is not that great.
Zipping a single .gif or .jpeg is pointless, and zipping Windows
installers is also not very productive.

This also works the other way; if you provide multimedia material in
a format that is not supported by many operating systems, you will
be locking people out or promoting Microsoft.

> Content-Type: text/html;

140 lines of semi-proprietory Word 2000 gibberish deleted.
Received on Thursday, 24 January 2002 16:50:01 UTC

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