brainstorming

[bobyrne at iol.ie]

Benjamin,

Thank you, that is now clear.

Does the patent clause in the Apache License 2.0 come close to your needs?
As I understand it, it is designed to prevent any user of Apache-licensed
software from suing any contributor to the project for infringement of
patents implemented in the project.

Perhaps that could be extended somehow? Something along the lines of:
Where a derivative work implements innovations claimed in patents owned by
the licensee, licenses to all relevant patents must be made available
without royalty to all contributors to this licensed work.

IANAL, so I have no idea how a court would view such language, but is that
the sort of thing you are aiming for?

Brian.
http://www.iol.ie