The GPL (v3) license covers the OpendTect system excluding closed source commercial plugins. The software is released with its source code (C++), is not protected by a license manager, and can be used by anyone, including for commercial purposes. Software developed under this license is per definition covered by the GPL (v3) license.
Commercial License
The commercial license covers OpendTect optionally extended with closed source commercial plugins. These plugins offer unique functionalities and work flows. Commercial users can either purchase or lease the closed source plugins that are protected by license managing software and they are given priority access to maintenance & support. Software developed under this license can be kept closed source when commercialized.
The academic license is intended for universities only. These can obtain free access to OpendTect and all of the commercial plugins that are released through the OpendTect website. The license can only be used for research & development and educational purposes. Software developed under this license can be kept closed source if this is a required condition of the project in which the research is conducted.