it's not that simple, one has to argue that the whole software is its own work and not simply an extension of the library. Quoting LGPLv3: > An “Application”

it's not that simple, one has to argue that the whole software is its own work and not simply an extension of the library. Quoting LGPLv3: > An “Application” is any work that makes use of an interface provided by the Library, but which is not otherwise based on the Library. Defining a subclass of a class defined by the Library is deemed a mode of using an interface provided by the Library. making a simple wrapper of a large LGPLv3 library is a more-than-grey area with the "not otherwise based on" wording.