Red Hat Linux 6.2E (Zoot), 27 March 2000
Red Hat Enterprise Linux 2.1 AS (Pensacola), 2002-03-26[15]
Update 1, ????-??-?? (Release Notes)
Update 2, ????-??-?? (Release Notes)
Update 3, ????-??-?? (Release Notes)
Update 4, ????-??-?? (Release Notes)
Update 5, ????-??-?? (Release Notes)
Update 6, 2004-12-13 (Release Notes)
Update 7, 2005-04-28 (Release Notes, redhat-release-as-2.1AS-121.src.rpm)
Red Hat Enterprise Linux 2.1 ES (Panama), May 2003
4.1, also known as Update 1, 2005-06-09
Red Hat Enterprise Linux 3 (Taroon), 2003-10-22. Uses Linux 2.4.21 (Release notes also for updates)
Update 1, 2004-01-16
Update 2, 2004-05-18
Update 3, 2004-09-03
Update 4, 2004-12-21
Update 5, 2005-05-20
Update 6, 2005-09-28
Update 7, 2006-03-15
Update 8, 2006-07-20
Update 9, 2007-06-15
Red Hat Enterprise Linux 4 (Nahant), 2005-02-15. Uses Linux 2.6.9
4.1, also known as Update 1, 2005-06-09 (Release Notes)
4.2, also known as Update 2, 2005-10-05 (Release Notes)
4.3, also known as Update 3, 2006-03-07 (Release Notes) (Release Notes on centos.org)
4.4, also known as Update 4, 2006-08-11 (Release Notes)
4.5, also known as Update 5, 2007-05-01 (Release Notes)
4.6, also known as Update 6, 2007-11-15 (Release Notes)
4.7, also known as Update 7, 2008-07-24 (Release Notes)
4.8, also known as Update 8, 2009-05-18 (Release Notes)
4.9, also known as Update 9, 2011-02-16 (Release Notes)
Red Hat Enterprise Linux 5 (Tikanga), 2007-03-14. Uses Linux 2.6.18 (Release notes)
5.1, also known as Update 1, 2007-11-07 (Release Notes)
5.2, also known as Update 2, 2008-05-21 (Release Notes, single file)
5.3, also known as Update 3, 2009-01-20 (Release Notes)
5.4, also known as Update 4, 2009-09-02 (Release Notes)
5.5, also known as Update 5, 2010-03-30 (Release Notes)
5.6, also known as Update 6, 2011-01-12 (Release Notes and Errata for release)
5.7, also known as Update 7, 2011-07-21 (Release Notes and Errata for release)
Red Hat Enterprise Linux 6 (Santiago), 2010-11-10 Uses Linux 2.6.32 (Release Notes).
6.1 also known as Update 1, 2011-05-19 (Release Announcement)