GNU General Public License Version 2

The GNU General Public License, version 2, is the second version of the GNU GPL, released in June 1991. The GPL is a copyleft license, which means that it guarantees end users the freedom to run, study, share or modify the software, but if you distribute a derivative work or modification you must provide the source code to those recipients under the same or equivalent license terms. The GPL was the first copyleft license available for general use and was originally written by Richard Stallman, the founder of the Free Software Foundation, for the GNU Project. Version 2 was released together with a second license, the GNU Library General Public License, numbered version 2 to show that the two licenses were complementary.