THE HISTORY OF COPYLEFT

       Though copyleft now extends to such diverse media as blogs, paintings, songs, and television broadcasts, it originated with computer software.  In the 1980s, “portable software” programs that could run on different types of computers emerged, allowing users to modify and redistribute the software.  This, however, conflicted with the existing business models of software companies, which lead to an increase in copyrighted programs with explicit limits on the modification and redistribution of the software.  For many programs, the source code was no longer available for viewing (or modifying) by interested users. 

       At that time, a hacker by the name of Richard Matthew Stallman (then commonly known as “RMS”) was working as a programmer at the Massachusetts Institute of Technology Artificial Intelligence Laboratory (commonly referred to as the MIT AI Lab).  Specifically, Stallman and his peers were working on a “Lisp interpreter” program (Lisp being a computer programming language) for creating and modifying software.  When some of his peers split from the group to pursue the project on their own terms, they asked Stallman for a public domain version of the source code for the program, which they then improved upon.  

      When Stallman requested access to this code with the improvements, he was denied by the group, called Symbolics.  In 1984, Stallman decided to counter this problem, which he called “software hoarding,” by working within the existing legal framework of copyright law.  He left the MIT AI Lab to dedicate more of his time to what he called the GNU project (the name coming from what eventually became the GNU/Linux operating system).  

      The result was the first copyleft license, the GNU General Public License (GPL).  While not recognized at that time as a “copyleft license,” the GPL enabled the software designer, if they wished, to grant all subsequent users of their work the rights to modify and redistribute the software.  

       Stallman then started the non-profit Free Software Foundation (FSF), which “is dedicated to promoting computer users' rights to use, study, copy, modify, and redistribute computer programs” by promoting the development and use of free software. 

       The GNU GPL became the most widely-used license for free software in the world, and the idea has since spread to other forms of media through a variety of licenses and organizations. These groups are dedicated to making it easier for individuals to selectively share and allow redistribution and modification of their works, ranging from paintings to songs, to novels, and in a growing number of ways.  
(https://www.msu.edu/~dinkgra2/copyleft-dinkgrave.pdf?q=copyleft)