Doors.NET has a demo mode feature that allows you 30 days of limited, basic operation. This can give you an opportunity to try the software before obtaining a license. Demo mode supports all hardware/controller types (except legacy PXLs) but includes only 1 x concurrent gateway and is limited to 500 cardholders.
You do NOT need a license key or an active Internet connection to activate the software in demo mode. You simply run the License Manager Wizard and then click the Demo button.