Pre-1980s In the early times of software, sharing of software and source code was common in certain communities, for instance academic institutions. Before the US Commission on New Technological Uses of Copyrighted Works (CONTU) decided in 1974 that "computer programs, to the extent that they embody an author's original creation, are proper subject matter of copyright", software was not considered copyrightable. Therefore, software had no licenses attached and was shared as
public-domain software. The CONTU decision plus court decisions such as
Apple v. Franklin in 1983 for
object code, clarified that the Copyright Act gave computer programs the copyright status of literary works and started the
licensing of software. Free-software licenses before the late 1980s were generally informal notices written by the developers themselves. These early licenses were of the "
permissive" kind.
1980s In the mid-1980s, the
GNU project produced
copyleft free-software licenses for each of its software packages. An early such license (the "GNU Emacs Copying Permission Notice") was used for
GNU Emacs in 1985, which was revised into the "GNU Emacs General Public License" in late 1985, and clarified in March 1987 and February 1988. Likewise, the similar GCC General Public License was applied to the
GNU Compiler Collection, which was initially published in 1987. The
original BSD license is also one of the first free-software licenses, dating to 1988. In 1989, version1 of the
GNU General Public License (GPL) was published. Version2 of the GPL, released in 1991, went on to become the most widely used free-software license.
1990s to 2000s Starting in the mid-1990s and until the mid-2000s, the
open-source movement pushed and focused the free-software idea forward in the wider public and business perception. In the
Dot-com bubble time,
Netscape Communications' step to release its webbrowser under a FOSS license in 1998, inspired many other companies to adapt to the FOSS ecosystem. In this trend companies and new projects (
Mozilla,
Apache foundation, and
Sun, see also
this list) wrote their own FOSS licenses, or adapted existing licenses. This
License proliferation was later recognized as problem for the
Free and open-source ecosystem due to the increased complexity of
license compatibility considerations. While the creation of new licenses slowed down later, license proliferation and its impact are considered an ongoing serious challenge for the free and open-source ecosystem. From the free-software licenses, the GNU GPL version2 has been tested in to court, first in Germany in 2004 and later in the US. In the German case the judge did not explicitly discuss the validity of the GPL's clauses but accepted that the GPL had to be adhered to: "If the GPL were not agreed upon by the parties, defendant would notwithstanding lack the necessary rights to copy, distribute, and make the software 'netfilter/iptables' publicly available." Because the defendant did not comply with the GPL, it had to cease use of the software. The US case (
MySQL vs Progress) was settled before a verdict was arrived at, but at an initial hearing, Judge Saris "saw no reason" that the GPL would not be enforceable. Around 2004, lawyer
Lawrence Rosen argued in the essay ''Why the public domain isn't a license'' that software could not truly be waived into public domain and can't be interpreted as very permissive FOSS license, a position which faced opposition by
Daniel J. Bernstein and others. In 2012, Rosen accepted the
CC0 as
open source license and conceded that copyright can be waived away, backed by
Ninth circuit decisions. In 2007, after years of draft discussion, the GPLv3 as major update of the GPLv2 was released. The release was controversial due to the significant extended scope of the license, which made it incompatible with the GPLv2.
MySQL,
BusyBox,
Blender,
VLC media player) decided against adopting the GPLv3. On the other hand, in 2009, two years after the release of the GPLv3,
Google open-source programs office manager Chris DiBona reported that the number of open-source projects licensed software that had moved to GPLv3 from GPLv2 was 50%, counting the projects hosted at
Google Code.
2010s In 2011, four years after the release of the GPLv3, 6.5% of all open-source licensed projects were GPLv3 while 42.5% were still GPLv2 according to Black Duck Software data. Following in 2011
451 Group analyst Matthew Aslett argued in a blog post that copyleft licenses went into decline and permissive licenses increased, based on statistics from Black Duck Software. In 2015 according to Black Duck Software == Definitions ==