Plugins are objects that can extend the functionality of bnd. They are called from inside bnd when a certain action should take place. For example, bnd uses a repository and plugins provide the actual repository implementations. Or for example, the SpringComponent analyzes the Spring files and adds references found in that XML to the imports.
A plugin is defined as:
PLUGIN ::= FQN ( ';' \<directive\|attribute\> )*
The following directive is defined for all plugin:
||A path to the jar file that contains the plugin. The directory/jar at that location is placed on your classpath for that plugin.|