From: brabuhr@...
Date: 2008-02-19T09:22:20+09:00
Subject: Re: OT: Why are .zip files so much bigger than tar.gz files?

On Feb 18, 2008 6:53 PM, Trans <transfire@gmail.com> wrote:
> So I has started to offer .zip packages of my projects to make life a
> little easier for Windows folks --seeing as it's no sweat off the
> backs of Linux folks either (unzip) --but then I noticed that zip
> files are huge. I have a 1MB tar.gz that's over 3MB as a .zip. Can
> that really be right?

Yes, it sounds like it can really be right.  A zip archive compresses
each file indivually and then adds them to the archive, this makes it
easy to extract indivdual files later [1].  A tar.gz archive adds all
the files to the tar and then gzips everything at once, this takes
advantage of cross-file redundancy for a better overall compression
ratio [2].

[1] http://en.wikipedia.org/wiki/.zip
[2] http://en.wikipedia.org/wiki/.tar  http://en.wikipedia.org/wiki/.gz