OSS Issues

0.
IP: Copyright + Patent
Licence: Contract, not just fee.

1.
copyleft: It have the mandatory rule: giving the user the privilege of
admission. e.g. GPL, but not ASF for that it not limit the user'
publish license after adding some modifications to the source code.
copyright: the privilege of the admission only owned by creator.

Patent: ***
It's powerful and the IP protections for the OSS developer. It protect
idea and the product of your thought but not the implementation.
From the view of software development, It give the protection to the
USE CASEs of your product.

2.
These are different:
Open Source Software，
Free Software, Share software...
essentially, all these issues about the contract content.