Developer and Site Licenses.
AddTapi.NET is licensed per developer. A license is required for each developer who will use AddTapi.NET. You are only required to purchase a license for each developer who develops or maintains the portions of your applications which use AddTapi.NET.

The Site license allows an unlimited number of developers to use AddTapi.NET at one physical street address.

Royalty Free Distribution.
The AddTapi.NET license agreement allows you to embed and distribute AddTapi.NET within your application, royalty free. Once you purchase a license for each developer, you may distribute AddTapi.NET with your application without any additional fees.

Professional v Enteprise
AddTapi.NET Professional is limited to 2 lines per computer/server.
AddTapi.NET Enterprise works with any number of lines supported by the telephony hardware.

Updates and Support
All licenses include lifetime free technical support and free upgrades for one year.
After one year new versions are available for purchase at special upgrade pricing.