Re: On another (but related) note: Zip files
- Date: Wed, 30 Aug 2017 08:24:29 -0400
- From: Greg Wooledge <wooledg@xxxxxxxxxxx>
- Subject: Re: On another (but related) note: Zip files
On Wed, Aug 30, 2017 at 11:14:59AM +0100, Darac Marjal wrote:
> I think it's down to the Freeness of the format. When PKZip was first
> released, it was shareware (meaning that the binary is provided free of
> charge, but there would be a "nag" message telling you to buy the product).
> GZip has always been free (probably GPL, but Wikipedia doesn't make that
> clear). Therefore, in the early days of Linux, gzip was the preferred
> format, because the compressor/decompressor was available for free.
Gzip implements the user interface and semantics of the proprietary
Unix compress(1) program, rather than the MS-DOS PKZIP program.
Where compress(1) placed a .Z extension on its compressed files, gzip
places a .gz extension.
Also noteworthy, gzip/gunzip can uncompress Unix .Z files. It was
intended as a drop-in replacement for compress(1) and uncompress(1).
Your point about licenses is a bit off the mark. It's about patents,
not software licenses.
compress(1) used the patented LZW compression algorithm (patent expired
in 2003), while gzip used the DEFLATE algorithm, which was also patented
(by PKWARE, no less!), but which can be "implemented readily in a manner
not covered by patents". <https://tools.ietf.org/html/rfc1951>