Here are release notes for each major release of WordPress.
- WordPress 4 "Benny" released on September 4, 2014
- WordPress 3.9 "Smith" released on April 16, 2014
- WordPress 3.8 "Parker" released on December 12, 2013
- WordPress 3.7 "Basie" released on October 24, 2013
- WordPress 3.6 "Oscar" released on August 1, 2013
- WordPress 3.5 "Elvin" released on December 11, 2012
- WordPress 3.4 "Green" released on June 13, 2012
- WordPress 3.3 "Sonny" released on December 12, 2011
- WordPress 3.2 released on July 4, 2011
- WordPress 3.1 released on February 23, 2011
- WordPress 3 "Thelonius" released on June 17, 2010
- WordPress 2.9 released on December 19, 2009
- WordPress 2.8 released on June 11, 2009
- WordPress 2.7 "Coltrane" released on December 11, 2008
- WordPress 2.6 released on July 15, 2008
- WordPress 2.5 released on March 29, 2008
- WordPress 2.3 released on September 27, 2007
- WordPress 2.2 released on May 16, 2007
- WordPress 2.1 "Ella" released on January 22, 2007
- WordPress 2 released on December 31, 2005
- WordPress 1 released on January 3, 2004