Re: rar 7z for dired-compress-file-suffixes and dired-compress-files-alist

[Noam Postavsky <npostavs@gmail.com>]

On 12 June 2018 at 12:42, Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Óscar Fuentes <ofv@wanadoo.es>
>> Date: Tue, 12 Jun 2018 18:05:31 +0200
>>
>> > Yes, AFAIK the full-featured versions that run on Windows are not Free
>> > Software, and the Free variants are not capable of opening archives
>> > one finds nowadays.
>>
>> 7z is LGPL/public domain.
>
> AFAIK, not all of the code that went into the Windows binary was under
> that license.  But maybe my information is stale

https://www.7-zip.org/license.txt says:

  7-Zip Copyright (C) 1999-2018 Igor Pavlov.

  The licenses for files are:

    1) 7z.dll:
         - The "GNU LGPL" as main license for most of the code
         - The "GNU LGPL" with "unRAR license restriction" for some code
         - The "BSD 3-clause License" for some code
    2) All other files: the "GNU LGPL".

[...]

  unRAR license restriction
  -------------------------

    The decompression engine for RAR archives was developed using source
    code of unRAR program.
    All copyrights to original unRAR code are owned by Alexander Roshal.

    The license for original unRAR code has the following restriction:

      The unRAR sources cannot be used to re-create the RAR
compression algorithm,
      which is proprietary. Distribution of modified unRAR sources in
separate form
      or as a part of other software is permitted, provided that it is clearly
      stated in the documentation and source comments that the code may
      not be used to develop a RAR (WinRAR) compatible archiver.