This special build of TXR for Microsoft Windows is linked against the Cygnal
library which is distributed inside the installer and installed together
with TXR. Cygnal is a patched derivative of the Cygwin library. This
build of TXR is is also linked against a redistributable GCC runtime which
comes from Cygwin. Neither Cygnal nor the GCC redistributable run-time are a
component of TXR; the TXR source code base contains no portion of these
libraries, and other ports of TXR to other platforms do not use them.

Cygwin is Copyright (C) 1995-2016 Red Hat Inc. and the Cygnal version
is distributed and used with TXR in accordance with the Lesser GNU Public
License (LGPL), Version 3 <https://cygwin.com/COPYING.LIB>.

The Cygnal project is hosted at <http://www.kylheku.com/cygnal>.

The redistributable GCC runtime is also under the Lesser GNU Public License,
and is Copyright (C) 2016 The Free Software Foundation, Inc.