PC World posted a news story that Microsoft has prohibited developers from using GPLv3-licensed open source software in any application distributed on the Windows Phone Marketplace.
The Windows Phone Marketplace Application Provider Agreement says applications "must not include software that ... in whole or in part, are governed by or subject to an Excluded License," and says excluded licenses "include, but are not limited to the GPLv3 Licenses."Microsoft to WP7 App Developers: Use Our Open Source Licenses