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) 1995-2024 Red Hat Inc. and the Cygnal version is distributed and used with TXR in accordance with the Lesser GNU Public License (LGPL), Version 3 . The Cygnal project is hosted at . The redistributable GCC runtime is also under the Lesser GNU Public License, and is Copyright (C) 2024 The Free Software Foundation, Inc.