One software license is required per developer.
Run-time royalty free.

Site Wide licenses cover all developers at one building.
Enterprise Wide licenses cover all developers in an organization, wherever they are in the world.
Source Code License provides current version source code - purchasers must hold a developer license.

Keyoti Maintenance includes upgrades for 12 Months. Customers with a current version can purchase an annual Maintenance susbcription. Existing Maintenance subscriptions can renewed with a 30 day grace period, after that you will need to purchase an upgrade.