Support and subscription:
With the delivery scope of the Professional Edition includes a 12-month subscription, which includes free updates and a top-level support (Support requests via mail / phone - in German or English - which mainly processed. A maximum 2 business days response, but usually processed immediately).
This subscription isn't renewed automatically, but can be extended in time by the customer.
Developer licenses are available, which you can use per user in unlimited number of projects and also deliver to your customers (within the meaning of the EULA).
System requirements (depending on the version):
♦ Microsoft .NET Framework 4.5.2 or higher
♦ Java JRE 1.8 / JDK 8 or higher
♦ Visual Studio 2012 oder newer
♦ Eclipse Oxigen oder newer