Following a prolonged dialog with the Wikimedia Foundation, the Free Software Foundation has recently published a new version of the GNU Free Documentation License (GFDL). This version was specifically released in order to allow Wikimedia projects to relicense their content under the Creative Commons Attribution-ShareAlike (CC-BY-SA) license.
All text in Wikipedia is licensed under the GFDL. When Wikipedia was first created, this was probably the most suitable free licensing scheme available. However, GFDL was originally designed for software manuals; its applicability to short encyclopedic articles is not always optimal. For example, while one is allowed to print and distribute copies of GFDL-licensed documents, the full text of the GFDL (approximately five printed pages) must be included with each copy.
CC-BY-SA is similar in spirit to GFDL: both allow the modification and reuse of content, including commercial use, as long as the original contributors are attributed and the free license is not removed. One practical difference is that CC-BY-SA allows copying documents while providing only the URL of the license. Many newer non-Wikimedia wikis, such as Wikitravel, Citizendium, and WikiEducator, are licensed under CC-BY-SA, making it unlawful to transfer content to and from these websites.
As a consequence, there has been an ongoing discussion in Wikimedia about the possibility of migrating to CC-BY-SA. Last December, the Wikimedia Foundation formally requested that GFDL be altered to allow this migration (see archived story). This is possible since Wikipedia's license text (like many other GFDL-licensed documents) specifies that the content may be reused under version 1.2 of the GFDL, or any later version.
GFDL 1.3, released on November 3, is the result of negotiations between the Wikimedia Foundation and the Free Software Foundation. This version defines a new concept, "massive multi-author collaboration websites," which refers to any website with "facilities for anybody to edit" its content—in other words, wikis and wiki-like sites. Under some restrictions, the operators of such websites are allowed to migrate all of their content to CC-BY-SA.
Two restrictions on this migration process are relevant to Wikipedia. First, the migration must take place no later than August 1, 2009. Second, GFDL-licensed material which was transferred to Wikipedia from a non-wiki source after GFDL 1.3 was published is not eligible for relicensing. According to the GFDL 1.3 FAQ, this limitation was included to prohibit "gaming the system by adding FDLed materials to a wiki, and then using them under CC-BY-SA afterwards." In a post on foundation-l, Wikimedia Foundation Deputy Director Erik Möller said that the latter restriction "was a key condition for the Free Software Foundation to agree to this change."
Discussion concerning the possibility of CC-BY-SA licensing began on foundation-l moments after GFDL 1.3 was released. The Foundation's plan is to collaboratively construct a re-licensing proposal on meta-wiki, which will release all content under a dual GFDL/CC-BY-SA license. According to Möller, "It is expected that we will launch a community-wide referendum on this proposal, where a majority will constitute sufficient support for re-licensing." Möller has also stated that "either all or no GFDL-licensed Wikimedia wikis will be switched to CC-BY-SA," to ensure that content can be easily transwikied.
Some Wikimedians have expressed worry about the clause prohibiting further inclusion of GFDL-licensed material. In response, Möller said, "If some GFDL 1.2 content that cannot be migrated later is imported by accident, that should not present any great difficulty—we will simply remove it as we would remove any other problematic copyrighted content."