How to license reuse of existing Omeka plugin?


#1

Hello. I am working on a plugin that uses an existing Omeka plugin as a starting point for further development. The resulting plugin serves an alternative purpose so this is not an ‘enhanced’ version of the same plugin. The existing plugin which lays some of the foundation for the one I am working on is, https://github.com/omeka/plugin-CollectionTree. Many aspects of the new plugin are different and additional code has been added for desired functionality. I am wondering how I would handle the license information for this once the plugin is completely finished. Have others done similar things, using existing plugins for building blocks in constructing a new plugin? If so, how has that been handled as far as the license and attribution. Thx. --Eric


#2

CollectionTree, like pretty much all the Omeka team’s work, is GPLv3 licensed. As GPL is a “copyleft” license, your plugin must also use the GPLv3 license.

Attribution is a closer call, I think it would be up to you to determine how far you’ve diverged and so on… I would imagine from your description that listing yourself or your organization as the sole author (i.e., in the plugin.ini) but making some sort of acknowledgement in the README of the use of CollectionTree as a basis would be appropriate, as well as maintaining existing copyright statements (to which you can/should of course add your own).


#3

Thanks for this information and feedback. It does help me move forward with this aspect of the work.