As anyone following this site closely must know, the Wikipedia community and Wikimedia Foundation board approved the adoption of the Creative Commons Attribution-ShareAlike (CC BY-SA) license as the main content license for Wikipedia and other Wikimedia sites. A post about the community vote has many links explaining the history and importance of this move.

Detail of Win win relationship by Alex Brollo / CC BY-SA

Starting last week with English Wikipedia (there are over 700 Wikimedia sites in over 250 languages — the image to the right is sourced from one of them), the copyright notice on Wikimedia sites is being changed to CC BY-SA. See the Wikimedia Foundation Terms of Use.

The outreach effort to non-Wikimedia wikis to take advantage of this migration opportunity is ongoing. Help if you can. One very important milestone was reached June 19, when most wikis hosted by Wikia (there are thousands, including some big ones) converted to CC BY-SA.

Hooray for Jimmy Wales, founder of both Wikipedia and Wikia! (Note the two organizations are unrelated.) CC is fortunate to also have Wales as a member of our board of directors. Without his vision, this unification of free culture licensing would not have been possible.

Here’s to a huge win for Wikipedians, all of free culture, and everyone who made it possible! Already the licensing change is enabling content to flow between Wikipedia and other projects. Will you interoperate? See a post on my personal blog for a long-winded conjecture about long-term impacts of the licensing change.

Finally, note that this is only one instance of the Wikipedia community showing great foresight and leadership. For example, clearly the Wikipedia community’s steadfast commitment to open formats played a major role in giving open video (effectively meaning Theora) a chance for wide adoption, which it now appears on the verge of. Hooray for visionary free culture communities and many wins to come!

Addendum 2009-06-30

Erik Moeller writes on the Wikimedia Foundation blog that the licensing update has been rolled out on all Wikimedia wikis:

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.