Any repository with a plugin.xml and plugin.properties files is considered as a plugin by GroIMP. To be properly loadable though, the plugin.xml needs to include:

<?xml version="1.0" encoding="UTF-8"?> 
<plugin id="your.plugin.id" 
version="x.x" 
xmlns="http://grogra.de/registry" >

where plugin id and version need to be filled with the plugin information.

A plugin has to have a special directory layout. The layout depends on how you run GroIMP. There are currently two layout:

1. As compiled plugin.
2. As compiled classes.

In the compiled version of GroIMP (the one deployed and installed with the executable files) the plugins are loaded as:

• MyPlugin
  • MyPlugin.jar
  • plugin.properties
  • plugin.xml
  • doc/
  • dependencies.jar …

In the development version of GroIMP (usually what you get from the source code, and using the –project-tree argument) the plugins are loaded as:

• MyPlugin
  • target
    • classes
      • plugin.properties
      • plugin.xml
      • <compiled class files>
      • <additional files copied from the src-directory>
    • lib
• <needed jar-files>

Important: Note that the files plugin.xml, and plugin.properties are required.

By default GroIMP load plugins from its root/plugins directory. During development, usually the –project-tree argument is used, making GroIMP load plugin from the same directory as the needed GroIMP plugins and projects (e.g., Graph, XL-Core, IMP-3D, …). It is also possible to set an additional directory where GroIMP look for plugins in the GroIMP preferences. Or by passing the command line argument -p when starting groimp.