This license document summarizes the key terms of the GNU Lesser General Public License (LGPL) version 2.1. The LGPL is intended to guarantee users' freedom to share and change free software, including specially designated software libraries. It allows developers to use and modify libraries under less restrictive terms than the ordinary GNU General Public License, permitting linking of LGPL libraries into non-free programs. The precise terms and conditions for copying, distributing, and modifying LGPL-covered works are then outlined.