The official license of the OctoMY™ project is now inspired by the official Qt project licence, namely a dual license that is either LGPLv3 or proprietary. Anyone can use OctoMY under the terms of the LGPLv3, while there exists a proprietary license just in case we need that at some point.
NOTE: Some parts of the OctoMY source code will always be under open source licenses only.
You can see the full OctoMY license here.
So why was this model chosen? Two reasons. First of all, the LGPL license guarantees everyone involved full access to the source code forever. It puts the O in Open Source.
Secondly the proprietary license prepares the project to accept contributions from sponsors that may have a hard time approaching a purely open source project. This is purely preemptive, we don't plan to accept such contributions at this time.