Within less than a year, a wordpress core developer changed wordpress’s licensing statement again. This time it has been changed from GPL to GPL v2+. The Changeset was :
WordPress contains libraries only available under the GPL v2 or later. No one cares about the GPL v1 anymore. We are now specifically saying that WordPress is available under the GPL version 2 or (at your option) any later version. This was discussed with the entire core team.
Next to the changeset in the wordpress core package, the text of the of the wordpress.org licensing terms has been changed.
The change done by Mark Jaquith is promoted as “Clarification in Licensing Language”. He explains that in an associated blog post.
In that post he is talking about licensing problems that result from the fact that wordpress has been using GPL version restricted library code (as it is the case for the KSES library which terms have been technically violated) while the package was not version restricted.
The core team wants to solve the issue now by distributing worpdress under GPL v2 or later which is matching the libraries own version specification.
The debate about the GPL version came on topic in August 2010 when I made a change of the GPL version in Februrary more prominent. That time it was a change from GPL to GPL v2 done by Andrew Nacin which got reverted after my report by Mark Jaquith in the end.
The worpdress copyright and licensing terms were subject to change a few times in the past.
Read On: WordPress License Clarified – Weblogs Tool Collection (16 Jan 2011; by James Huff)
Follow Up: CiviCRM and WordPress (28 Jan 2011; by hakre)