---
key: cygwin-exception-2.0
short_name: Cygwin exception to GPL 2.0
name: Cygwin exception to GPL 2.0
category: Copyleft Limited
owner: Cygwin Project
homepage_url: http://cygwin.com/licensing.html
is_exception: yes
spdx_license_key: LicenseRef-scancode-cygwin-exception-2.0
text_urls:
    - http://cygwin.com/cgi-bin/cvsweb.cgi/src/winsup/CYGWIN_LICENSE?cvsroot=src
standard_notice: |
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License (GPL) version 2, as
    published by the Free Software Foundation.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
    *** NOTE ***
    In accordance with section 10 of the GPL, Red Hat permits programs whose
    sources are distributed under a license that complies with the Open
    Source definition to be linked with libcygwin.a without libcygwin.a
    itself causing the resulting program to be covered by the GNU GPL.
    This means that you can port an Open Source(tm) application to cygwin,
    and distribute that executable as if it didn't include a copy of
    libcygwin.a linked into it. Note that this does not apply to the cygwin
    DLL itself. If you distribute a (possibly modified) version of the DLL
    you must adhere to the terms of the GPL, i.e. you must provide sources
    for the cygwin DLL.
    See http://www.opensource.org/docs/osd/ for the precise Open Source
    Definition referenced above.
    Red Hat sells a special Cygwin License for customers who are unable to
    provide their application in open source code form. For more
    information, please see: http://www.redhat.com/software/cygwin/, or call
    +1-866-2REDHAT ext. 45300 (toll-free in the US).
    Outside the US call your regional Red Hat office, see
    http://www.redhat.com/about/contact/ww/
---

In accordance with section 10 of the GPL, Red Hat permits programs whose
sources are distributed under a license that complies with the Open
Source definition to be linked with libcygwin.a without libcygwin.a
itself causing the resulting program to be covered by the GNU GPL.