Xref: news2.mv.net comp.os.msdos.djgpp:6692
From: lehmann AT mathematik DOT th-darmstadt DOT de (Alexander Lehmann)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: MSDOS Unzip Program
Date: 29 Jul 1996 17:34:55 GMT
Organization: Technische Hochschule Darmstadt
Lines: 30
Message-ID: <4tisnv$139h@rs18.hrz.th-darmstadt.de>
References: <4tgq4k$bt0 AT news DOT uni-paderborn DOT de> <31FAD0AE DOT 503 AT ix DOT netcom DOT com>
NNTP-Posting-Host: fb0408.mathematik.th-darmstadt.de
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

iNFiK <randolp1 AT ix DOT netcom DOT com> wrote:

: thoes freeware ZIPers are based on the original pkware PKZIP program.
: and pkzip is freeware unless you use it in a buisness or somthin =-] .. i 
: think....

Actually, PKZIP is based on LHA 2.x, much more than zip is based on
PKZIP. When LHA 2.x was released (which was basically a quantum leap
in compression), pkzip got a new compression method which about
equaled LHA, and since the source code of LHA was available, I would
guess that the author at least was inspired by it (which is ok, since
Yoshi released LHA a public domain).

The unzip program, which was the base for free zip/unzip was
programmed without any information about the format itself (at least
that's what I have heared), they basically reinvented the algorithm
based on the knowledge of LHA. Now, while the file format is certainly
an invention of PKWARE, the zip program has added long file names,
upper/lower case and symbolic links (for unix).


bye, Alexander

PS. maybe we should RFC alt.advocacy.zip?

-- 
Alexander Lehmann,                                  |  "On the Internet,
alex AT hal DOT rhein-main DOT de  (plain, MIME, NeXT)         |   nobody knows
lehmann AT mathematik DOT th-darmstadt DOT de (plain)          |   you're a dog."
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