Thoughts about Open Source Licensing

[edit] The sipX project chose L-GPL as its license

SIPfoundry and the sipX project have deliberately chosen LGPL as the open source license:

GPL is considered viral: The sipX project explicitly wanted to enable third parties (including commercial entities) to use sipX code and link it with their own code without forcing this code to become open source
LGPL provides reciprocity: LGPL still provides the vital provision of reciprocity, which means that derivative work comes back to the community
OSI approved: LGPL is an OSI approved open source license, compatible with the large base of both GPL and LGPL code already out there

In particular, choosing LGPL has the following distinct advantages:

No extensions are required to allow linking against third party (proprietary) code such as commercial codecs and other things. If sipX was GPL such linking would not be possible without violating the GPL license

Re-use of sipX components: As an objective SIPfoundry wants to accelerate adoption of standards based SIP solutions. To that effect, choosing LGPL as the open source license for sipX specifically allows commercial entities to use components of sipX in commercial products provided that changes and improvements to such components are given back to the community.

SIPfoundry and the sipXecs project require contributors to sign a contributor agreement. The purpose of this contributor agreement is to establish code provenance. If open source code is to be used in production environments by commercial entities, liability issues have to be dealt with. Being able to prove where any piece of code came from is crucial in this context.

I hope this helps clarify some of the misunderstandings out there.