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