On June 15, the site-footer and various other messages in the English Wikipedia were changed to reflect the licensing change that the Wikimedia community overwhelmingly approved last month: from the GNU Free Documentation License as the primary content license to the Creative Commons Attribution Share-Alike License (CC-BY-SA). Creative Commons founder Larry Lessig tweeted that it was the “first copyright message ever to bring tears” to his eyes, and Mike Linksvayer called it a “free culture win” in the Creative Commons blog.

A few other Wikimedia wikis and projects have followed in a bottom-up manner, but today we standardized the site language to ensure that all our projects in all languages reflect the new terms (see this message for some more internals about the process). Want to translate text from the Italian to the Spanish Wikipedia? Both are CC-BY-SA. Use content from Wiktionary? It’s CC-BY-SA. A textbook from the French Wikibooks? CC-BY-SA.

Perhaps the most significant reason to choose CC-BY-SA as our primary content license was to be compatible with many of the other admirable endeavors out there to share and develop free knowledge: projects like Citizendium (CC-BY-SA), Google Knol (a mix of CC licenses, including CC-BY and CC-BY-SA), WikiEducator (CC-BY-SA), the Encylcopedia of Earth (CC-BY-SA), the Encyclopedia of the Cosmos (CC-BY-SA), the Encyclopedia of Life (a mix of CC licenses), and many others. These communities have come up with their own rules of engagement, their own models for sharing and aggregating knowledge, but they’re committed to the free dissemination of information. Now this information can flow freely to and from Wikimedia projects, without unnecessary legal boundaries.

This is beginning to happen. A group of English Wikipedia volunteers have created a WikiProject Citizendium Porting, for example, to ensure that high quality information developed by the Citizendium community can be made available through Wikipedia as well, with proper attribution.

The world of free knowledge doesn’t end with Wikipedia, and it shouldn’t. Indeed, license compatibility is just one part of a functioning, decentralized free knowledge ecosystem. Incidentally, with the exception of Google Knol and EOL, all of the aforementioned projects use MediaWiki, the open source collaboration software developed and maintained by the Wikimedia Foundation – so, we are well-positioned to help further develop this ecosystem of knowledge in the future.

Erik Moeller
Deputy Director, Wikimedia Foundation