Does free-as-in-freedom software endanger proprietary software?

This resource is a wikidebate, a collaborative effort to gather and organize all arguments on a given issue. It is a tool of argument analysis or pro-and-con analysis. This is not a place to defend your preferred points of view, but original arguments are allowed and welcome. See the Wikidebate guidelines for more.

Note: In the title of the debate, we use the less ambiguous "free-as-in-freedom software" title for what is usually called "free software" for increased clarity. An alternative term would be FOSS: free/open-source software.

Free-as-in-freedom software endangers proprietary software

Pro

• Argument for Since GNU GPL is arguably a viral license, one would think it would spread and eventually as if infect all software.
  • Objection This is a naive and inconclusive argument, not borne out by experience after decades of success and deployment of free software.
  • Objection The license can spread from libraries to applications using the libraries (assuming the kind of linking that makes the license spread), but it is not clear how it can spread from an application to another application. Moreover, the license does not spread from an operating system to applications running on it.
  • Objection Permissive free-as-in-freedom licenses are also widely used and, in the viral analogy, are a competing virus blocking the spread of GNU GPL. For instance, Python 3rd party libraries available in PyPI repository are often permissively licensed.

Con

• Argument against Even after all the success of the Linux kernel or a more extended GNU/Linux operating system, Microsoft Windows is still going strong.
  •  Comment On the other hand, proprietary Unix providers suffered greatly from Linux.
• Argument against Despite the availability of OpenOffice/LibreOffice and the open specification of the Microsoft office formats, Microsoft Office (Word, Excel, Powerpoint) is still going strong.
• Argument against Free-as-in-freedom software forces are most active only in some software segments, especially platform/tool segments such as operating system kernels, operating system tools, compilers, non-compiled programming languages, libraries, web browsers, etc. For instance, they are much less active/successful in end user desktop application software.
• Argument against Expanding on the above. It is not clear how FOSS forces could penetrate firmware for industrial devices.
• Argument against Expanding on the above, as for business software, Oracle, SAP and Microsoft are still going strong and there does not seem to be anything like a threat from free software.
• Argument against Expanding on the above, despite the great success of gcc compiler suite and later LLVM (and clang), Microsoft is still supplying its own proprietary compilers.
• Argument against Expanding on the above, antivirus software does not see any threat from FOSS at all.
• Argument against Expanding on the above, GIMP did not eliminate Adobe's Photoshop business.
• Argument against Expanding on the above, GNU Octave did not eliminate MATLAB (Octave aims at MATLAB compatibility).
• Argument against Expanding on the above, FreeMind and Freeplane did not eliminate MindManager and other proprietary mind mappers.
• Argument against Expanding on the above, Python's numpy and sympy in Jupyter notebooks did not eliminate proprietary mathematical packages.
• Argument against Expanding on the above, free Java Virtual Machine (and Java) have not displaced Microsoft's .NET (and C#), although the latter seems much less popular.
• Argument against Expanding on the above, even after decades of free software, Apple's App Store is teeming with proprietary paid software and so does Google Play.

Further reading

• Will open source compete with proprietary software until all proprietary software become open source?, quora.com