Microsoft has a deep history of trying to undermine open source software, and companies that use open source software. Companies that use the GNU/Linux operating system and supporting software have been targeted with various software patent lawsuits. Yet, Microsoft has publicly stated that it fully supports open source. But its actions continue to show distaste for it.
Today I read a blog post mentioning Microsoft's agreement for submitting applications to the Windows Phone Marketplace. Deep inside this agreement, there are specific clauses that mention applications governed by the GNU General Public License v3 are not allowed. I cracked open the document from Microsoft's website to verify this was in fact true, and it is.
So here we have in plain print, that Microsoft wants nothing to do with GPL (GNU General Public License) with Windows Phone. The GPL promotes open and free software, as it encourages many individuals to contribute to produce a single and quality product. There are thousands upon thousands of quality applications for different platforms (Linux, Windows, Android, Mac OSX, etc.) that fall under the GPL and are very well done. The GNU/Linux operating system itself falls under the GPL. So essentially, Microsoft is thumbing its nose at open source applications and closing the door on them. This essentially hurts the customer, as free and open applications will not be allowed to be downloaded to their phone through the Marketplace.
I would only have to assume that Microsoft extends these same feelings to their Windows operating systems on PC hardware as well. And this is one of many reasons I choose GNU/Linux over Windows. Not only does Microsoft govern and control the way users use its software, but they limit the software as well. The GPL ensures that you are not going to be limited or controlled by one entity, and that the software remains open and free for all users to use, study, distribute, learn, and tinker with. Ultimately, it opposes putting limits on software as Microsoft likes to do.