Over the years we had a lot of contribution and support requests but didn't see any project contribution, nor any source code from others then the team. It is hard for opensource projects to become such popular that a couple of contributors seriously contribute code or actively work within the core team.
A license change to a more restrictive license like the LGPL, could be an enabler to enforce this, on the other hand we still want to be attractive for companies as much as possible that OpenWMS.org is used by them. So we have to find a trade off between wishes and requirements.
Mike Millinkovic (Eclipse Foundation) has convinced me, that the EPL is the legally and formally better OSS license than LGPL. That is also business friendly and does not force a company to give something back. It is designed to be used for modular software system (like the Eclipse IDE) and fits to OpenWMS.org as well (http://en.wikipedia.org/wiki/Eclipse_Public_License).
Nevertheless the task is to change all source code, license files and website information to GPLv2 license!