What if the guy using your framework wants to add other php projects like JpGraph, or some image management? This may be impossible depending on the licensing of these other items
Once project where this became important is Agata php report writer and JpGraph which was changed to the QPL. Thus it is impossible for Agata (GPL) to use new versions of JpGraph.
When I license my framework under LGPL then it is allowed to combine my script with Agata php report writer or the JpGraph???
Roland