SSM-OSGV Open Design Agreement
"OSGV technical data (documentation, designs, computer models, simulations, test results, etc.) will be distributed under a GPL-like public license, called the SSM-OSGV Open Design Agreement:
Licensees may view, adapt, modify and redistribute SSM-OSGV technical data, however, any technical data derived from SSM-OSGV technical data must also be governed by the same SSM-OSGV license and made available to the public through an SSM-OSGV approved medium (e.g. osgv.org).
Except when the interface specification remains intact: the new part conforms to its source control / specification control / interface control drawings; only then the private entities may retain the proprietary status of design." (http://www.osgv.org/open-design-model/)