What are the license(s) of the Linux man pages?
Solution 1:
It depends on the specific manpage. For example, the manual pages for socket, send, and recv (in general anything in section 2) are part of the kernel and documented as part of the kernel documentation. While gethostbyname is a glibc function, it too is documented as part of the kernel.org manpages on my system. I suspect this is because the GNU people are not interested in manpages as a primary documentation format, and focus their efforts on Texinfo.
In general, you should look at the specific manpage you are quoting to find its specific license. socket/send/recv have BSD licenses whereas the gethostbyname manual has the "verbatim" license. To find the specific license and the copyright owner, you need to look in the manpage source itself.
From /usr/share/man/man3/gethostbyname.3.gz:
.\" Copyright 1993 David Metcalfe (david@...)
.\"
.\" Permission is granted to make and distribute verbatim copies of this
...(goes on for four paragraphs, then lists references and change history)
From /usr/share/man/man2/send.2.gz:
.\" Copyright (c) 1983, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
...(rest of four-clause BSD license, then change history)
You should, however, look at the source code comments for the work you are quoting/copying, rather than relying on claims that someone else makes about the manpages installed on their system.
You should also note that if you are using the text of the manpage, you may have to add a copyright notice. From the verbatim license:
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
The BSD license requires you to include the entire license, and may require you to include "This product includes software developed by the University of California, Berkeley and its contributors." in your advertising materials. In general you need to read and follow the license terms on each manpage you are using. You should talk to a lawyer if you are unsure of how to comply with the terms of the licenses.
(And not all manpages have the same author - check each individual page for the copyright statement near the top.)
You can view manpage source with zless /usr/share/man/man[section]/[file].[section].gz. Older distributions may have it under /usr/man instead of /usr/share/man, and may not have the files gzipped.
Solution 2:
What is the license on the Linux man pages? GPL, Public Domain, etc?
All submissions to man-pages must be licensed using a license that permits the page to be freely redistributed and modified. Include that license or a reference to it, in the source code of the man page.
There are many such licenses, but in the interests of minimizing the number of licenses in man-pages, it is preferred that you use one of the following:
The "verbatim" license (personal preference of the current maintainer, and seems also to have been the preference of the previous maintainer as well)
The GNU General Public License (GPL)
The BSD License
man-pages does not include pages under the GNU Free Documentation License (GFDL). This is a purely pragmatic decision, made because the GFDL is problematic for Debian, one of the largest distributions.
The rest of the above link includes examples of each of the three licence types mentioned.
Source Licenses for man-pages
It's all about the glibc network functions
The GNU C Library, commonly known as glibc, is the GNU Project's implementation of the C standard library.
The GNU C Library documentation licence can be found at http://www.gnu.org/software/libc/manual/html_mono/libc.html#Documentation-License.
The GNC C library documentation can be found at http://www.gnu.org/software/libc/manual/html_mono/libc.html and is covered by the above mentioned licence.
Solution 3:
According to kernel.org, it must be licensed as freely available work:
All submissions to man-pages must be licensed using a license that permits the page to be freely redistributed and modified. Include that license or a reference to it, in the source code of the man page.
Solution 4:
From kernel.org:
All submissions to man-pages must be licensed using a license that permits the page to be freely redistributed and modified. Include that license or a reference to it, in the source code of the man page.
There are many such licenses, but in the interests of minimizing the number of licenses in man-pages, it is preferred that you use one of the following:
The "verbatim" license (personal preference of the current maintainer, and seems also to have been the preference of the previous maintainer as well)
The GNU General Public License (GPL)
The BSD License
man-pages does not include pages under the GNU Free Documentation License (GFDL). This is a purely pragmatic decision, made because the GFDL is problematic for Debian, one of the largest distributions.
kernel.org is maintained by the Linux foundation.