I just discovered this article:
The cynical among us could even see this policy as a strike by Red Hat against a whole class of competing free operating systems. That is almost certainly not the case: Red Hat is just trying to ensure that its patent weapons can actually be used. As the company told us:
We elected to specifically exclude licenses that don't expressly prohibit open source code from being incorporated into proprietary code. Absent that stance, the patents would be of little benefit.
I don't see where is the source of this statement.
