which license to use for software using components with GPL, LGPL and EPL?

[Chris Travers]

On Mon, Aug 31, 2009 at 4:12 AM, Ian Vernon<ian.vernon at amanzitel.com> wrote:
> We are writing a software platform that uses components that are licensed
> udder GPL, LGPL and EPL. Both FSF and EF claims that GPL and EPL are not
> compatible, while we want to release the software platform as open as
> possible we would not want to redo 18 calendar months (I know we should have
> checked license conditions early on) of work due to a potential license
> incompatibility between GPL and EPL. From various posting the
> incompatibility seems to have risen from the definition of derivative works.
> Having said what do you think are our choices for licensing?

The first thing to do is talk to a lawyer.  The GPL and EPL are not
compatible but the communities also have different ideas of when the
licenses matter.  The fact of the matter is that there are big
questions regarding WHEN the GPL requires that a component is under
the GPL as well.

Basically there are three issues here:
1)  You don't want to be sued (win or lose)
2)  You don't want to lose a lawsuit.
3)  You want to maintain good relations with the community.
(Extra-copyright issues are important here)

You also need to make sure you ask the right questions and talk to the
owners of the code too AFTER you talk to the lawyer.  Questions I
would suggest asking include:

1)  Is this a derivative work?  Do I need to worry about these
licenses from a perspective of losing a legal battle?

2)  How can we avoid questions of derivative works from a legal
perspective?  What does derivative work mean with regard to software
and linking?

IMO, (this is business advice, not legal advice) once you have a grasp
of the legal side of things, you should contact the owners of the GPL
components and ask for separate permission to distribute them as part
of your platform.   If you can get that permission, document it in the
license file for your product.  My sense is that most developers who
use the GPL tend to be reasonable in this area, but there are a few
zealots out there.

If you can't get permission, then you need to figure out a)  how much
time a replacement will cost, b) what the risk of looking bad to the
community are for you, and c) what the risks of being sued are.  This
means looking at things both on your development side and discussing
them with a lawyer.  Most likely the choice will be to replace those
components you can't get the developer's blessing to use.

In most cases I have seen, most GPL licensors are happy to allow other
open source products to use their works, and they appreciate being
asked.

Best Wishes,
Chris Travers