From owner-freebsd-hackers Wed Jan 24 17:49:03 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id RAA10587 for hackers-outgoing; Wed, 24 Jan 1996 17:49:03 -0800 (PST) Received: from relay5.UU.NET (relay5.UU.NET [192.48.96.15]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id RAA10582 for ; Wed, 24 Jan 1996 17:48:59 -0800 (PST) Received: from uucp5.UU.NET by relay5.UU.NET with SMTP id QQzzzb28146; Wed, 24 Jan 1996 20:48:53 -0500 (EST) Received: from uanet.UUCP by uucp5.UU.NET with UUCP/RMAIL ; Wed, 24 Jan 1996 20:48:53 -0500 Received: by crocodil.monolit.kiev.ua; Thu, 25 Jan 96 03:46:06 +0200 Received: (from dk@localhost) by dog.farm.org (8.6.11/dk#3) id DAA13513; Thu, 25 Jan 1996 03:32:53 +0200 Date: Thu, 25 Jan 1996 03:32:53 +0200 From: Dmitry Kohmanyuk Message-Id: <199601250132.DAA13513@dog.farm.org> To: nate@sri.MT.net (Nate Williams) Cc: freebsd-hackers@freebsd.org Subject: Re: FBSD 2.1 Newsgroups: cs-monolit.gated.lists.freebsd.hackers Reply-To: dk+@ua.net X-Newsreader: TIN [version 1.2 PL2] Sender: owner-hackers@freebsd.org Precedence: bulk In article you wrote: > > > Copyrights. I don't particularly feel like tangling with either PKWARE > > > or UniSys (LZ compression used in Zip). > > > > The InfoZip zip/unzip is fairly generous with their copyright conditions, > > and they are fairly confident that they are not violating UniSys' or > > PKWare's patents. > I just spend the last few minutes looking through the sources, and it > appears that ZIP doesn't use LZ, but LZW. Apparently they are different > enough to be safe from Copyright problems. well, since I've spent 4 years studying data compression .... ;-) zip uses implode algorithm which is LZ77 aka LZ for compression. unzip supports both LZW (aka LZ768) decompression and LZ77 decompression (and older compression methods left as compatibility with pkzip <1.93 made archives). Unisys patent applies only to LZW. So, it applies to compress(1), GIF format, but not zip. You can just check with Info-Zip team (and specifically, Mark Adler and Jean-Loup Gailly) about this. -- The number you have dialed is imaginary. Please rotate your telephone ninety degrees and try again.