Microsoft restricts use of open source in apps

Microsoft has banned three types of open-source licence from its Windows Phone Marketplace.

The restriction is written in the applications requirements that developers must meet in order to have their app accepted in Windows Phone Marketplace.

The clause was discovered by Red Hat's EMEA evangelist Jan Wildeboer, who wrote about the issue in his blog.

In the terms, Microsoft states that "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."

This means that developers cannot use libraries that fall under the "excluded license" or use documentation that is licensed under it.

Excluded licenses include GPLv3 Licenses. This refers to 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.

"So each and all 'equivalents' to the GPLv3, LGPLv3, Affero GPLv3 license are excluded. Any license that requires redistribution at no charge is excluded," said Wildeboer.

"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," he said.

"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. This should make app developers think again about whether this mobile platform is their platform of choice."