LGPL (GNU Lesser General Public License) is a free software license published by the Free Software Foundation. The LGPL provides a more permissive alternative for the strictly copyleft GPL . While any derivative work using a GPL-licensed program must be released under the same terms (free to use, share, study, and modify), the LGPL only requires the LGPL-licensed component of the derivative program to continue using the LGPL, not the whole program. LGPL is usually used to license shared components such as libraries (.dll , .so , .jar , etc.).