Does using the LGPL mean that all additions to OpenCms must be Open Source as well?
OpenCms has a build in module API (which is in fact a Java interface). All modules that use that API are in terms of the LGPL “works that use the library” and therefore are not bound by the LGPL license. However, if additions or changes to the core system are made, the result is a derivative work, and certain restrictions apply, the most important being that the license used for the derivative work must also be the LGPL. So companies can develop their additions to OpenCms as a module and choose any license they like. However, the OpenCms core system and all enhancements or additions to it will stay Open Source.
