Developing an open-source alternative to the UNIX operating system in the early 1980s, the master hacker Richard Stallman faced a dilemma: if he put his new GNU software in the public domain, people could copyright their improved versions, undermining the open-source cycle by taking away the freedoms he’d granted. So Stallman copyrighted GNU himself, and distributed it, at no cost, under a license that arguably was to have greater impact on the future of computing than even the software he was striving to protect. The GNU Emacs General Public License was the founding document of the copyleft. The word copyleft predated Stallman’s innovation by at least a couple of decades. It had been used jestingly, together with the phrase “All Rights Reversed,” in lieu of the standard copyright notice on the Principia Discordia, an absurdist countercultural religious doctrine published in the 1960s. And in the 1970s the People’s Computer Company provocatively designated Tiny BASIC, an early experiment in open-source software, “Copyleft—All Wrongs Reserved.” Either of these may have indirectly inspired Stallman’s phrasing. (He first encountered the word copyleft as a humorous slogan stamped on a letter from his fellow hacker Don Hopkins.) Stallman’s genius was to realize this vague countercultural ideal in a way that was legally enforceable. That Stallman was the one to do so, and the Discordians weren’t, makes sense when one considers his method. His license stipulated that GNU software was free to distribute, and that any aspect of it could be freely modified except the license, which would mandatorily carry over to any future version, ad infinitum, ensuring that GNU software would always be free to download and improve. “The license agreements of most software companies keep you at the mercy of those companies,” Stallman wrote in the didactic preamble to his contract. “By contrast, our general public license is intended to give everyone the right to share GNU Emacs. To make sure that you get the rights we want you to have, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights.” Freedom was paradoxically made compulsory.