Given that a software patent can be implemented in different ways, languages and platforms then what are the license requirements of the implemented pieces of software?
Is it possible that the patent owner releases an open source implementation or this would necessary invalid the patent rights because open source licenses grant freedom of use, distribution and modification?
Since Apache License allows to distribute derivative works under a proprietary license, then is it compatible with the patent rights to build an implementation of the patent software as a derivative work from a piece of software released under Apache license? What about the mandatory copyright notices?
Is there a difference in this regard if instead of a derivative work as a whole an extension module is released? In this case the proprietary module wouldn't work without the Apache license parent application, but isn't it almost the same when somebody releases a proprietary application in PHP (the application wouldn't work without the under running open source PHP interpreter)?
What is the best license to release an implementation of a software patent to not interfering with patent protection?