Hello,

there are two aspects: technical and licensing:

1) technical
If you developed a web site in Kentico CMS 1.x, you need to wait for the migration toolkit that will allow you to upgrade version 1.9 to 2.1. it will be available after 2.1 release at the end of November 2006.

2) licensing
The free upgrade is provided to customers who have a valid subscription for their license. The others need to purchase an upgrade at http://www.kentico.com/Buy/Upgrades.aspx.

Best Regards,