[pp.int.general] Patent system similar to GPL?

[Richard Stallman]

    The base technology remains the property of whoever the patent belongs to.
    All those who agree to the same terms of sharing obtain access to
    improvements, and other information (such as regulatory and biosafety data).

Yes, you can do that.  It might be useful, but it is not very similar
to copyleft.

It cannot reach trolls.  Also, if a company creates a separate patent
troll company, and they are both held by the same holding company, it
may be able to escape from these requirements -- unless someone very
clever figured out a way to prevent that.

Are you involved in designing these licenses?

-- 
Dr Richard Stallman
President, Free Software Foundation
51 Franklin St
Boston MA 02110
USA
www.fsf.org, www.gnu.org