Good debate at www.fossic.org, between advocates for GPL, BSD and EPL (Eclipse Public License). At the end of the debate, there were not a lot of new reasons to consider or dismiss any of them, but it was useful to revisit the arguments. A couple of the better statements: (1) if you are not redistributing code, we’re all BSD (2) business models (for software companies) largely follow licensing choices, and (3) the major impact of GPL is to create trust in a developer community.

Regarding (1) – no argument there. All of the licenses grant more or less complete autonomy when your intended use is for internal purposes. I’m a little surprised that no one decided to take on the question of what is internal use as we move more and more to cloud computing and software as a service. (I just listened to the vignettes, so may have missed it if they did).

Regarding (2) – again no argument. The statement actually was in support of the EPL, which is a “weak” copyleft style of license, meaning that you can build on top of EPL licensed software without the requirement to contribute back your code. There are a number of companies that do exactly this with EPL code – IBM the most prominent. The clear business model that EPL supports is one that benefits from broad adoption. A GPL-based business model gives developers more leverage and control about how their product is distributed, and a BSD model is really an outgrowth of government sponsored R&D whose mission is to create intellectual property that can be widely reused with minimal restrictions.

Regarding (3) – I think the trust point is correct in the sense that contributors to a GPL project know that their code will always remain GPL, and that the restrictions on distribution give them a clear view of how their code will be used. I think there is a more pragmatic view as well – and that is that GPL gives software firms a clear way to achieve wide visibility and potentially community, and a very strong starting point for a commercial discussion where appropriate. That commercial discussion could be “buy a support contract”, or it could be “if you want to redistribute my software with yours under terms other than GPL, you’ll need a commercial license”.