You may choose a non-commercial license if you use the software for non-commercial purposes in non-business, non-commercial environment. You should purchase a business license to use the software in a corporate, government, or business environment.
Single license means that a copy of the software is allowed to be used only on a single computer and only by a single user at a time. If you wish to use the software for more than one user, you will need a separate license for each individual user (click the "Order now" button to see volume discounts). Site license means that the software is allowed to be used without limitation on count of installations and users within one organization.
All our products and bundles are shipped with 12 months of free upgrades (minor and major ones) or with 36 months of free upgrades for a quite small additional fee.