The InfoNode Docking Windows framework is available under a dual license. We have compiled some questions and answers regarding licencing in our Sales FAQ.

In effect InfoNode's dual licensing strategy says that if you are writing a GPL application use the GPL version of InfoNode Docking Windows, otherwise you must use the version distributed under the InfoNode Software License and purchase one or more developer licenses.

GNU General Public License (GPL)
The GPL version are distributed to the open source community under the terms of the GPL. This license is intended for developing, building, and distributing open source software. The GPL release of InfoNode Docking Windows allows free software developers to use InfoNode Docking Windows free of charge. Any software produced with the GPL version of InfoNode Docking Windows (and any derivatives of this software) must also be released with full source code available under the GPL.
InfoNode Software License
The InfoNode Software License allows customers to develop and distribute their applications under standard commercial terms for a fee. The commercial license is based on developer license. You may copy and distribute the complete InfoNode Docking Windows without modifications together with a product if all persons that have developed any part of the product that uses InfoNode Docking Windows directly or indirectly have purchased a developer license for InfoNode Docking Windows. Please read the InfoNode Software License for details.