6.3.0 - 08/15/2012
6.2.3 - 05/04/2012
6.1.0 - 11/07/2011
6.0.7 - 08/30/2011
3.0.0 - 02/04/2011
2.3.12 - 02/01/2011
2.2.11 - 01/05/2011
2.2.10 - 11/17/2010
2.1.15 - 09/08/2010
2.1.9 - 05/26/2010
2.0.13 - 04/07/2010
2.0.11 - 03/02/2010
1.3.6 - 11/04/2009
1.2.6 - 07/24/2009
1.1.4 - 05/15/2009
1.0.4 - 03/11/2009
It's a lot of updates, but it's been around a while too. The big jumps usually represent significant changes to the system.