OpenVDB is released under the Mozilla Public License Version 2.0, which is a free, open source, and detailed software license developed and maintained by the Mozilla Foundation. It is a hybrid of the modified BSD license and the GNU General Public License (GPL) that seeks to balance the concerns of proprietary and open source developers.
Contributor License Agreement
Developers who wish to contribute code to be considered for inclusion in the OpenVDB distribution must first complete this Contributor License Agreement and submit it to DreamWorks (directions are in the CLA). We prefer code submissions in the form of pull requests to the OpenVDB GitHub repository. All code should adhere to the OpenVDB coding standards, and every commit must be signed off. That is, every commit log message must include a “Signed-off-by” line (generated, for example, with “git commit --signoff”), indicating that the committer wrote the code and has the right to release it under the MPL 2.0 license. See http://developercertificate.org/ for more information on this requirement.