I am starting to work on a new commercial software project that may use elements of "open source" code.

I have been instructed to ensure that I only use code which is licensed for commercial use and although we may decide to make it open source in the future it should be required to be open source.

So this clearly prohibits the use of any true copyleft licensed code.

But this got me wondering; are there any standard "open source" software licenses that allow commercial use, but do not allow redistribution of source?

I have intensionally used quotes around open source as I am aware that any licenses that fit this criteria cannot be compatible with the accepted OSI definition of open source.

  • 5
    I think even a common sense definition of open source would exclude any license that forbids redistribution of source. Licenses like that are usually called closed source. Jan 29, 2014 at 1:50
  • @GregHewgill While I completely agree, I'm still curious at the possibility!
    – zelanix
    Jan 29, 2014 at 1:51
  • Do you mean you must redistribute source with it! or you must redistribute it under the license, if you distribute the source? The later sounds BSDish, which is open source too.
    – user40980
    Jan 29, 2014 at 5:24
  • Note: it is irrelevant if your sofware is commercial or not. That is orthogonal to the problem of free vs. proprietray software.
    – user91642
    Feb 4, 2014 at 12:12

2 Answers 2


There are no open-source licenses that do not allow the redistribution of source; that's a contradiction in terms. What there are, though, are non-viral open-source licenses that do not require the redistribution of source.

It sounds like what you're looking for is code with a license less "strong" than the GPL family. Have a look at the MPL (Mozilla Public License), which requires you to publish any changes you make to the MPL code itself but doesn't care about the rest of the project you use it in, even if it's a commercial project. Also, there are a number of extremely permissive open-source licenses such a the MIT license, the BSD license and the Zlib license that have minimal restrictions on what you can and can't do with the code in question.

  • Thanks for the descriptions, I think that this is the closest to what I was looking for.
    – zelanix
    Feb 3, 2014 at 22:18

No, not that I ever heard of.

Your firm is looking for "dual license" code, code that is available EITHER under an open source license OR under a commercial license. When such code is acquired under a commercial license, the licensee generally is not obligated to release the source of his modifications to anyone.

With such code, your firm COULD elect in the future to release it as open source, provided of course that the various chunks you mix and match are all under compatible open source licenses, so that the final product can be licensed as a whole.

The odds are that your firm is going to find itself paying a LOT of money for those commercial licenses.

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