I asked Ed Walsh, an attorney whose specialties include open source software licensing, about current discussion draft of the GPLv3 license. Ed is an attorney with well-respected IP law firm Wolf, Greenfield & Sacks. Here's what he told me:
A summary of the way this draft balances concerns of competing constituencies can be found in the words of the drafters themselves, who state:
“Software patenting is a harmful and unjust policy, and should be abolished.”
With this philosophical bent clearly evident, it is hard to detect anything that should make businesses that own patents more comfortable about using software covered by the GPL. Rather, it should raise concerns that GPL licensed code is incompatible with objectives of for-profit business, or at the least trigger an awareness that the rules of Open Source have changed and it is time to re-evaluate both decisions whether to use open source and practices around how it will be used.
The suggestion that the requirement to grant patent licenses has been limited by a "contribution based licensing" is misleading because "contributions" are defined in GPLv3 to include the entire work, unless the work conveyed is a verbatim copy of a work made by someone else. Anyone who obtains a copy of the program or any portion of it is licensed. The license even applies to patents not in existence or owned when the work is conveyed. Further, new definitions of a "covered work" and "conveyance" expand the reach of the GPL beyond software or software distribution and likewise expand the situations in which a patent license must be granted.
If the current draft becomes final without significant changes in section 11 (Patents), inventors, entrepreneurs, investors, and other interested parties should be wary of relying on GPLv3. There are, of course, other open source licenses besides the GPL, and concerned parties should probably evaluate these licenses as well if open source is a part of their business strategy.
Back in January, Ed gave a presentation on Open Source Software: Issues for Start-ups to the Boston Entrepreneurs' Network that surveys the kinds of issues that should be taken into account. For the avoidance of doubt, this presentation had in mind GPLv2, and not the current v3 draft.