OpendTect software is released under a triple licensing scheme. The free part (OpendTect and the free plugins) is released under an open-source license agreement: GNU GPLv3 or higher.
OpendTect Pro and all commercial plugins are protected by FlexNet license managing software (see below). License keys for OpendTect Pro are always time-limited to the duration of a rental -, or maintenance period. Commercial plugins can either be perpetual (subject to a license fee and annual maintenance fee), or temporary (per month or per year. The Geoscience Package, a bundle of OpendTect Pro and numerous plugins by dGB can also be rented per day).