@booklet {517, title = {Claiming Copyleft in Open Source Software: What if the Free Software Foundation{\textquoteright}s General Public License (GPL) had been Patented?}, year = {2008}, month = {Jan}, abstract = {Patent law, by necessity, needs some way to evaluate inventiveness. Otherwise, it will grant rights to advances not worth ""the embarrassment of an exclusive patent."" The innovations of version two of the Free Software Foundation{\textquoteright}s (FSF) GNU General Public License (GPLv2), arriving in 1991, could not, under U.S. patent law at that time, have been meaningfully measured against patent law{\textquoteright}s criteria, often referred to as the five elements of patentability. The first element of patentability, statutory subject matter, would have excluded the GPLv2{\textquoteright}s copyright-based licensing technique as a ""business method."" A variety of industry developments in the decades following GPLv2{\textquoteright}s arrival, combined with the license{\textquoteright}s potent ideological force and clever use of copyright law, propelled FOSS licensing into a prominent and path-breaking place within information technology worldwide. Its force and presence, and lightning-rod character, have grown over time, with GPLv2 remaining the dominant license in mind-share, if not code-share. In addition, all of this occurred without patent protection for GPLv2{\textquoteright}s unique licensing technique. This then raises the counter-factual inquiry for this symposium article: what might have occurred differently if GPLv2{\textquoteright}s licensing method had been patentable? In other words, if the U.S. patent law of statutory subject matter in 1991 was sufficiently permissive, and if the FSF and Richard Stallman successfully patented the novel licensing approaches of GPLv2, would patent protection have altered the FOSS movement{\textquoteright}s two-decade trajectory through information technology and the Internet? If so, can we estimate in what ways? The Article{\textquoteright}s assessment is that GPLv2 could readily meet the other four elements of patentability (with non-obviousness being the closest call compared to prior sublicensing schemes), and that the FOSS trajectory would change minimally, due to a variety of factors, including practical constraints on the enforcement potency of patent claims to GPLv2, competition from other types of FOSS licensing, and strategic considerations for a variety of players and camps within the FOSS movement. However, in the counterfactual, license proliferation diminishes, and dual licensing may be foreclosed.}, attachments = {https://flosshub.org/sites/flosshub.org/files/Vetter.ClaimingCopyleftInOSS-WhatIfGPLPatented.2008Mich.St_.L.Rev_.279.pdf}, author = {Greg R Vetter} }