Microsoft: Absolutely NO (GPLv3-or-compat-licensed) Free Software for Windows Phone and Xbox Apps.

DISCLAIMER: I am not a lawyer and this is my PERSONAL blog. This article reflects my PERSONAL opinion and does not necessarily represent the position of my employer.

DISCLAIMER 2: Some articles that link here claim I say that *ALL* Open Source software is banned by Microsoft. That is NOT what I say. Please read on.

[UPDATE: Italian translation of this article by Guglielmo Troiano at “Microsoft: niente Software Libero per Windows Phone e Xbox Apps.” ]

[UPDATE 2: Seems that the terms from Microsoft also exclude their own MS-PL license as pointed out by @webmink in the comments and in this article and also by @fontana on – now THAT is cool if correct :-)]

This is rather uncool, IMHO, I stumbled upon this forum entry and was quite astonished. It points to the Microsoft Application Provider Agreement that governs the Windows Marketplace, the App Store where users can get apps and developers publish them.

Now here’s the fun part. In article 5, Microsoft explains the Application Requirements that you need to fulfill to get your app accepted in the marketplace. It’s point E that is of interest here:

e. The Application must not include software, documentation, or other materials that, in whole or in part, are governed by or subject to an Excluded License, or that would otherwise cause the Application to be subject to the terms of an Excluded License.

Note the full scope: in whole or in part. This means that you cannot use Libraries that are under this ominous “Excluded License”. Or use documentation that is licensed under the ominous “Excluded License”. You get the point. If you use whatever stuff that is under this ominous “Excluded License” your app will not be added to the marketplace.

Now what is this ominous “Excluded License”? Scroll back in the document and find:

“Excluded License” means any license requiring, as a condition of use, modification and/or distribution of the software subject to the license, that the software or other software combined and/or distributed with it be (i) disclosed or distributed in source code form; (ii) licensed for the purpose of making derivative works; or (iii) redistributable at no charge. Excluded Licenses include, but are not limited to the GPLv3 Licenses. For the purpose of this definition, “GPLv3 Licenses” means the GNU General Public License version 3, the GNU Affero General Public License version 3, the GNU Lesser General Public License version 3, and any equivalents to the foregoing.

So each and all “equivalents” to the GPLv3, LGPLv3, Affero GPLv3 license are excluded. Any license that allows requires redistribution at no charge is excluded.

The consequences of this strange exclusion are not fully clear to me as I am not a lawyer. But one thing is extremely obvious. Microsoft wants to keep its platform clear of Free Software. Period.

This coming from the company that publicly claims to be a friend of Open Source, that wants to make windows the best ever platform for Open Source should make app developers think again if this mobile platform is the platform of choice.


CC BY 4.0 This work is licensed under a Creative Commons Attribution 4.0 International License.

136 thoughts on “Microsoft: Absolutely NO (GPLv3-or-compat-licensed) Free Software for Windows Phone and Xbox Apps.”

    1. Read the comments on that article. The Author says in his last comment: “@Bill, Now its pretty clear. GPL & its derived licenses are banned” – so IMHO he has changed his viewpoint to what I offered 😉

    1. How is that more accurate? It repeats what I am saying. I never said all open source is forbidden on MSFT Marketplace, I said it is GPLv3, LGPLv3, Affero GPLv3 and equivalent – which is just quoting the terms. The comment you point to is no different from that AFAICS …

      1. You’re blaming Microsoft for this. Microsoft doesn’t have much of a choice. The GPLv3 license makes *itself* incompatible with app stores that have terms of use. As pointed out, other companies have been busted for *allowing* GPLv3 apps into their ecosystems

        1. The chicken and egg question – who was first? Well, copyleft licenses were first. So Microsoft (and Apple too) drafted their terms in a way that knowingly excludes copyleft licenses as the GPL. They could have done different, but they didn’t.

          This was not an oversight, omission or accident IMHO. Both Microsoft and Apple love BSD, MIT style Open Source but fundamentally dislike the copyleft system of Free Software.

          So IMHO I can blame Microsoft for this. They drafted their terms *after* the GPL, copyleft etc were created and used.

    1. Please do read the article you linked to. It states that I am right with my article here but that Thinq is wrong by extending my position (Copyleft, GPL) to ALL Open Source. To quote the very article you link to:

      […] the general consensus is that Microsoft has not in fact banned all open source, just the GPLv3 licence, and all its “derivatives and equivalents.”

      Now, you will note that that fact is nearly a direct quote from the original blog post […]

      So again, thenextweb reinstates what I say here and debunks what others made of it.

      1. That article does *not* say your position is correct, at least insofar as your position is still “one thing is extremely obvious. Microsoft wants to keep its platform clear of Free Software. Period.”

        As the article makes clear, that is not the point of the restriction at all. The reason for the restriction is that GPLv3 does not allow you to sell software in an app store unless it meets certain qualifications, and Microsoft’s App Store doesn’t meet them (because it uses anti-circumvention).

        The only “obvious” thing is that Microsoft doesn’t want software on its platform that would violate a license if it were to be sold on its app store. If the license effectively bans the MS App Store from being able to sell it, then it won’t get approved.

        1. I should also clarify that I am not saying the article is correct (I don’t know) — only that it does not agree with your conclusions.

  1. Does this mean that also earlier licenses such GPL v2.1 are prohibited or just GPL v3?

  2. > This coming from the company that publicly claims to be a friend of Open Source

    well… GLP3 (and any GNU license) is arguable “free” license as prohibits “something” on many levels.

    MIT license, BSD, Apache, or WTFPL are those trully free licenses that give you more freedom on using a software.

    GPL3 in particular, has statements that prohibit you to link software license using GPL3, with other software using non-GPL3 license, in this case Microsoft XNA license. So that’s pretty obvious why you cannot use GPL3, and one another reason to not use GPL3 in your software at all, if you wish to have your software available everywhere on any platform.

  3. The great thing I think most folks forget is that Win Mobile 7 is such a marginal platform in the mobile ecosystem right now that if they have the audacity to think that they will do their customers ‘one better’ than Apples totalitarian regime, the marketplace is simply going to hand them their ass. Not only that but watch how quickly the new shiny Nokia lovefest goes south!

    Go ‘head M$, get greedy like everyone else and see what it gets you.

  4. It’s simple, those licenses aren’t compatible with the licenses for the frameworks MS is using. MS would have to publish all their source code otherwise. Software based on completely free licenses is fine.

  5. Well spotted, and thanks for bringing it to peoples’ attention to at least do their own research on if they disagree. Luckily I have no desire to publish apps on WP7 and am quite happily on that other platform that couldn’t ban F/OSS if it wanted to. 🙂

  6. Hi Jan,

    I find your writing to be quite insightfull. You begin with stating that

    ‘DISCLAIMER 2: Some articles that link here claim I say that *ALL* Open Source software is banned by Microsoft. That is NOT what I say.’

    So, you seem to understand that certain OSS Licenses are OK and supported by Microsoft.

    All good.

    Then you finish your article by stating ‘Microsoft wants to keep its platform clear of Free Software. Period.’

    That is quite a silly statement given your DISCLAIMER

    Are you biased towards calling Microsoft bad names?


    1. Hello Wouter, long time no see! I guess the OOXML fun is now behind us?

      Seemingly you don’t know about the difference between Free Software and Open Source. Hint: Free Software is always Open Source, but not all Open Source is Free Software.

      Once you understand the difference, you see that my statement makes perfect sense. The terms are written in a way to make sure Free Software cannot enter the WP7 market. Which is exactly what I am saying.

      1. Well, then maybe the problem is Free Software is a very misleading term. Maybe you should start calling it what it is, open source with conditions. GPL is the least free “free license” there is.

        In my humble opinion.

        1. The FSF, GPL *defined* Free Software. Opensource came later. The blurring and muddying that the term “Open Source” caused is not the fault of the Free Software Foundation. The old, old war between BSD and GPL on who is more free is simply unsolvable. Whereas BSD etc claim to offer more freedom by having less conditions, Free Software claims to be more free as it uses more conditions to defend their freedom. It really is that simple. You have to make a choice. I made mine. To me Free Software is better. But I won’t attack others that chose the other way.

          1. I generally agree with your post and views, but on this particular point, I think you are misled. Free software as defined by the FSF also include BSD and MIT style licenses.

            What Microsoft doesn’t want on its platform is copyleft.

            People claiming that the reason to this is because apps have to link into framework code and that this isn’t possible under GPL terms (unless framework is GPL’ed) are also wrong IMHO.

            You can link to system’s file (IIRC the GPL FAQ has an example with the C runtime from Windows).

            There is plenty of GPL software for the .NET platform, which is a similar case.

  7. According to blogger Jan Wildeboer, Microsoft has specified in their Developer Agreement for the Windows Phone Marketplace, that apps that use open source technology are not allowed. This ban includes software “in whole or in part” that use GPL- and MPL-licenses among others. This means that the Windows Phone platform will become even more closed than iOS!

  8. can i give windows phone unsigned apps free to users through my microsoft will have any objection or can charge me any fine for that.i m using free tools for developing apps,provided by microsoft.

  9. I wonder why so many people always come to conclusions that are based on ideology rather than reason.

    Let’s assume Microsoft did not exclude GPL based software from its Windows Store. The consequences would be that Microsoft, as the distributor of that software, needed to actually comply with the GPL and provide a license compliant implementation in their distribution channel to cope with the freedoms that come with the GPL. That is A LOT OF HASSLE and would probably not work at all for practical reasons rather than ideology.

    Quoting from the blog post, another thing is obvious (once again):

    “This coming from the company that publicly claims to be a friend of Open Source, that wants to make windows the best ever platform for Open Source should make app developers think again if this mobile platform is the platform of choice.”

    Free Software (as in software governed by a license from the FSF) is NOT defining Open Source software. Microsoft does not exclude Open Source software from its platform, it excludes Free Software (as in FSF free) from their platform (and that’s me guessing: probably more for practical reasons than for ideology). You’re probably perfectly capable to submit BSD licensed, Apache licensed, MIT licensed etc. to the Windows Store.

    Maybe the FSF should rethink their own ideology and how it doesn’t fit the development and distribution of software in the real world.

    Apart from that, the Windows Store is not the only way to get software to a Windows 8 device (excluding phones at this point). A Desktop application can be distributed outside the Store. Also, modern Windows 8 apps can be “sideloaded” as I understand. There are probably a lot of caveats to consider. Common sense and detail matter study applies.

    Disclaimer 1: I am a Microsoft employee.
    Disclaimer 2: I am a long time FSFE Fellow.
    Disclaimer 3: This comment is my own personal view and does not reflect the view of my employer or any other organization I may have links to.

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