This license document summarizes the GNU Lesser General Public License (LGPL) version 2.1. The LGPL is intended to guarantee users' freedom to share and modify certain libraries and software while allowing them to be used in proprietary software through linking. It provides protections for distributors and users, requiring source code to be shared and rights to be maintained when modifications are made. The precise terms and conditions for using, copying, distributing and modifying works under this license are then defined.