Microsoft has banned GPLv3 open-source software from Windows Phone and Xbox apps, according to Jan Wildeboer, an open source evangelist and Red Hat employee. Jan Wildeboer ran across a forum entry and preceded to search through the Microsoft Application Provider Agreement to see exactly where Microsoft stood on the issue of different licenses within their own Marketplace.
The section in question comes from the Microsoft Application Provider Agreement in article 5, point E:
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 App to be subject to the terms of an Excluded License.
While at first this mayn't seem too odd or even unacceptable, it's the definition of just what an "Excluded License" is that becomes disappointing. Basically an "Excluded License" is any that requires the license to be distributed with the software subject to the license. This means your GPLv3, LGPLv3, Affero GPLv3, as well as any others that force coders to include the license with a distribution of the product.
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.
Why has Microsoft chosen to do this? According to Wildeboer the reasons are pretty clear:
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.