One software license is required per Server/user machine.
One license covers a single computer running under the selected operating system platform, regardless of the number of CPUs.
Development licenses for machines which are not used for production purposes are free with each purchase.
Redundant (backup) machines do not require a separate license, provided they are never used concurrently with the actual production machines.
Groups of load-balancing servers require a license for every server in the group.

Free desktop version for non-commercial use.TET PDF IFilter for desktop systems, i.e. Windows 2000/XP/Vista may freely be used for personal use, i.e. non-commercial purposes. Deploying the desktop version in any situation which can be considered commercial use requires a commercial license, though.
TET PDF IFilter for server operating systems, i.e. Windows Server 2000/20003/2008 always requires a commercial license.

Annual Support is available to purchase with new product licenses or to renew an existing support contract:
The support contract is for 12 months and includes:

• Technical support with short response times
• All minor (maintenance) and major (functional) updates
• Early availability of bug fixes