Basically, I have an idea for some software based on an Open Sourced application.

If I was to build an application based off of that, and sell my plugins, would this be a breach of terms? This is the flow in my head.

  1. The base application which would ingest the plugins is completely open sourced.
  2. The plugins would not use any part of the GPL licensed software.
  3. The plugins would be sold on a hypothetical marketplace and would be fully optional.
  4. I would also like to allow other people to sell their own plugins for the base software.

If this is an application you are developing, there's no problem: as the copyright holder, you can do whatever you like. If you want to permit other people to develop closed-source plugins for your application, it's recommended that you add an exception clause to your license statement (eg. "Plugins for MyApplication that use the documented plugin API can be developed even if doing so would otherwise violate the license terms for MyApplication"). See the GNU website for a couple of examples of exception clauses written by lawyers.

If this is an application that someone else has developed and has released under the GPL v2, things get more complicated. The GPL v2 doesn't clearly define what constitutes a "modified version", but many forms of plugin (such as a dynamically-loaded library) are generally considered modifications, and thus need to be licensed under the GPL v2.

  • Awesome thanks, I think that gives me a better idea here! – user3014687 Jan 20 '20 at 14:48

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