In the absence of dual-licensing, is there a way to encourage P2P or OS contributors to donate their time, money, and energy to the community, generating an common pool of open technology…while still allowing for-profit firms to create proprietary add-ons that need not go back into the community.
In other words, how do you incentivize both parties in a system that has an open core with proprietary fringes? P2Pers know that their work will forever remain available to all. Proprietary firms know that they can differentiate their products in the market place (if they make their own improvements).
From what I understand, a license like GPL does not allow this. If a for-profit firm adds in a miniscule snippet of OS code, this contaminates everything else the for-profit firm has created, and it must return "everything" back to the commons.
Is there a license out there that prevents contamination? And has that license generated successful ecosystems/projects with open innovators and proprietary commercializers existing side-by-side?