November 20th, 2008 – Alpha 1 release

December 18th, 2008 – Alpha 2 release

January 15th, 2009 – Alpha 3 release

February 5th, 2009 – Alpha 4 release

February 26th, 2009 – Alpha 5 release

March 12th, 2009 – Alpha 6 release

March 26th, 2009 – Beta release

April 16th, 2009 – Release Candidate

April 23rd, 2009 – Final release of Ubuntu 9.04