OSI and License Proliferation on fossbazar.com by Martin Michlmayr "Too many different licenses makes it difficult for licensors to choose: it's difficult to choose a good license for a project because there are so many. Some licenses do not play well together: some open source licenses do not inter-operate well with other open source licenses, making it hard to incorporate code from other projects. Too many licenses makes it difficult to understand what you are agreeing to in a multi-license distribution: since a FOSS application typically contains code with different licenses and people use many applications which each contain one or several licenses, it's difficult to see what your obligations are." (op 21 augustus 2008)
Frequently Asked Questions about the GNU Licenses – Is GPLv3 compatible with GPLv2?. gnu.org. Geraadpleegd op 3 juni 2014. “No. Some of the requirements in GPLv3, such as the requirement to provide Installation Information, do not exist in GPLv2. As a result, the licenses are not compatible: if you tried to combine code released under both these licenses, you would violate section 6 of GPLv2. However, if code is released under GPL “version 2 or later,” that is compatible with GPLv3 because GPLv3 is one of the options it permits.”
Shea, Tom, Free software - Free software is a junkyard of software spare parts. InfoWorld (23 juni 1983). Geraadpleegd op 10 februari 2016. ""In contrast to commercial software is a large and growing body of free software that exists in the public domain. Public-domain software is written by microcomputer hobbyists (also known as "hackers") many of whom are professional programmers in their work life. [...] Since everybody has access to source code, many routines have not only been used but dramatically improved by other programmers.""
Kerner, Sean Michael, Torvalds Still Keen On GPLv2. internetnews.com (2008-01-08). Geraadpleegd op 2015-02-12. ""In some ways, Linux was the project that really made the split clear between what the FSF is pushing which is very different from what open source and Linux has always been about, which is more of a technical superiority instead of a -- this religious belief in freedom," Torvalds told Zemlin. So, the GPL Version 3 reflects the FSF's goals and the GPL Version 2 pretty closely matches what I think a license should do and so right now, Version 2 is where the kernel is.""
corbet, Busy busy busybox. lwn.net (1 oktober 2006). Geraadpleegd op 21 november 2015. "Since BusyBox can be found in so many embedded systems, it finds itself at the core of the GPLv3 anti-DRM debate. [...]The real outcomes, however, are this: BusyBox will be GPLv2 only starting with the next release. It is generally accepted that stripping out the "or any later version" is legally defensible, and that the merging of other GPLv2-only code will force that issue in any case"
Kelty, Christpher M., The Cultural Significance of free Software - Two Bits 99. Duke University press - durham and london (2008). "Prior to 1998, Free Software referred either to the Free Software Foundation (and the watchful, micromanaging eye of Stallman) or to one of thousands of different commercial, avocational, or university-research projects, processes, licenses, and ideologies that had a variety of names: sourceware, freeware, shareware, open software, public domain software, and so on. The term Open Source, by contrast, sought to encompass them all in one movement."
Richard Stallman on "World Domination 201". Gearchiveerd op 3 juni 2013. Geraadpleegd op 24 maart 2018. “I cannot agree to that compromise, and my experience teaches me that it won't be temporary. ... What our community needs most is more spine in rejection of non-free software. It has far too much willingness to compromise. ... To "argue" in favor of adding non-free software in GNU/Linux distros is almost superfluous, since that's what nearly all of them have already done.”
Mark, The Curse of Open Source License Proliferation. socializedsoftware.com (2008-05-08). Geraadpleegd op 30 november 2015. "Currently the decision to move from GPL v2 to GPL v3 is being hotly debated by many open source projects. According to Palamida, a provider of IP compliance software, there have been roughly 2489 open source projects that have moved from GPL v2 to later versions."
Larabel, Michael, FSF Wastes Away Another "High Priority" Project. Phoronix (24 january 2013) Gearchiveerd op 9 november 2016. Geraadpleegd op 22 augustus 2013. "Both LibreCAD and FreeCAD both want to use LibreDWG and have patches available for supporting the DWG file format library, but can't integrate them. The programs have dependencies on the popular GPLv2 license while the Free Software Foundation will only let LibreDWG be licensed for GPLv3 use, not GPLv2."
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Interview with Richard Stallman. GNU/LAS s20e10. Linux action show (11 maart 2012). Geraadpleegd op 22 augustus 2014. “RMS: I’m not gone to claim that I got a way to make it easier to raise money to pay people who write free software. We all know, that to some extent there are ways to do that, but we all know that they are limited, they are not as broad as we would like.”