title: GPL, LGPL licencing
body: <p>My application uses 2 libraries (not modified). First one is under GPL and second one under LGPL. This means that my application needs to be released under GPL and LGPL because both libraries will be shipped along with my application. That's fine. Now, application exposes plugin infrastructure so anyone can write plugins for it. Plugins will not be able to communicate directly with those 2 libraries mentioned at the start of the text because they have no idea what is behind application. Plugins will not be shipped with application. Users will be able to choose which plugin they want to install from open/public plugin list thru application. </p>
  
  <p>Questions:</p>
  
  <ol>
  <li>Will plugins also need to be released under GPL?</li>
  <li>Is there any way to release some plugins under closed source code licence? Which one?</li>
  <li>What would be the best licence approach to prevent companies to write plugins that are free on the client (application) side and not free on the server side without commercial licence? (plugin calls web service that charges for service usage). In this case i would like company to pay some fee as in one hand this goes to commercial usage. For instance/example, someone has a web service that converts images between various formats. That someone writes plugin that requires user account information ( login ). Plugin connects to his web service, authenticates, convert image and charge user account for some amount. In this example plugin is free for installation and usage. It's users choice will he use it completely or not.</li>
  </ol>
  
  <p>Is something like this possible? </p>
  
  <p>Thanks.</p>