<qandadiv id="license-ptc">
<title>&title-license-ptc;</title>

<qandaentry>
<question id="q-what-licenses-apply">
<para>What licenses apply to &project; source code?</para>
</question>

<answer>
<para>&project; proper isn't covered by a single license, as &project;
is made up of two parts that are covered by distinct licenses:
&cygwin; and the &x-window-system;.</para>

<para>See <xref linkend="q-license-x-window-system"></xref> and <xref
linkend="q-license-cygwin"></xref> for more information regarding the
licenses that apply to &project;.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-license-x-window-system">
<para>What licenses apply to the &x-window-system; source code?</para>
</question>

<answer>
<para>&x-window-system; source code is generally licensed under an
<ulink url="&x-url-license;">X11 style license</ulink>, which is
<ulink url="&fsf-url-licenses;">certified by the Free Software
Foundation</ulink> as compatible with the <acronym>GNU</acronym>
<acronym>GPL</acronym>.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-license-cygwin">
<para>What license applies to &cygwin; source code?</para>
</question>

<answer>
<para>&cygwin; source code is
<ulink url="https://cygwin.com/licensing.html">
licensed under a modified version of the
<acronym>GNU</acronym> <acronym>GPL</acronym>
</ulink>.
&cygwin;'s license
modification specifically allows third-party software under an
<ulink url="http://opensource.org/licenses">
open source license
</ulink>
to be linked with &cygwin; without requiring that the
source code for the third-party software be distributed under the
terms of the <acronym>GNU</acronym> <acronym>GPL</acronym>.
&cygwin;'s developers went to great trouble to obtain this
modification and should be thanked for doing so, as without it the
modification, &project; linking to &cygwin; would be the subject of
endless discussion.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-copyright-cygwin-x">
<para>Who holds the copyright on the &project; source code?</para>
</question>

<answer>
<para>&project; proper doesn't have a single copyright holder, as
&project; is made up of two parts, namely &cygwin; and the
&x-window-system;; each part follows a different scheme in regards to
who will hold the copyright on source code.</para>

<para>See <xref linkend="q-copyright-x-window-system"></xref> and <xref
linkend="q-copyright-cygwin"></xref> for more information regarding who
holds the copyright on &project; source code.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-copyright-x-window-system">
<para>Who holds the copyright on the &x-window-system; source code?</para>
</question>

<answer>
<para>Each source code file in the &x-window-system; typically has its
own license and copyright statement.  Therefore, there is not a
general rule for determining who holds the copyright on a particular
&x-window-system; source file, as each author is free to assign the
copyright to someone else, to some group, or to keep the copyright
themselves.  You must inspect the source code file in question to
determine who holds the copyright for that file.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-copyright-cygwin">
<para>Who holds the copyright on the &cygwin; source code?</para>
</question>

<answer>
<para><ulink url="&redhat-home;">&redhat;</ulink> owns the copyright
on the &cygwin; source code.  &redhat; requires that copyright be
assigned to &redhat; for non-trivial changes to &cygwin;.  You must
fill out a copyright transfer form if you are going to contribute
substantial changes to &cygwin;.</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-motif-license">
<para>What license applies to &motif;?</para>
</question>

<answer>
<para>
&motif; is a product of <ulink url="&tog-home;">&tog;</ulink>.
After many years under the
<ulink url="&open-motif-url-license;">&tog-public-license;</ulink>
(which does not satisfy the
<ulink url="http://opensource.org/docs/osd/">Open Source Definition</ulink>
and is thus not compatible with Cygwin's license),
&motif; was released as free software under the LGPL v2.1 in October 2012.
</para>
</answer>
</qandaentry>


<qandaentry>
<question id="q-trademark-xwin">
<para>Isn't <quote>XWin</quote> trademarked by &starnet;?</para>
</question>

<answer>
<para>Not in the USA, at least.  A quick search at the <ulink
url="&uspto-home;">&uspto;</ulink> for <quote>XWin</quote> turns up
one dead record and one live record.  The live record is for a logo
belonging to a rock crusher manufacturer based out of Belgium.
Neither trademark affects &project;, as the dead record is no longer
enforceable, while the live record is in an unrelated and distinct
industry; there cannot be confusion between rock crushers and computer
programs.</para>
</answer>
</qandaentry>

</qandadiv>
