e3
Research could contain some POC application hosted at JazzTeamEdu, also some forum discussion (or here?).
Consider usage of OSGI (equinox?)
Sharing with some open source OSGI/plugin based implementations:
Apache felix apache OSGI
Corona project http://www.eclipse.org/corona/ provides the way to access Eclipse based project etc. at the OSGI runtimes, at the SOA environments.
Eclipse equinox Eclipse implementation of the OSGI with the extension for the plugins - exstended OSGI
Spring OSGI implementation
Knoplerfish http://www.knopflerfish.org/ Open Source OSGI related stuff
Also adding some plugin based links
Java Plugin Framework
http://www.java2s.com/Open-Source/Java-Document/Development/Java-Plugin-Framework/CatalogJava-Plugin-Framework.htm
http://jpf.sourceforge.net/
Java Simple Plugin Framework
http://code.google.com/p/jspf/
http://stackoverflow.com/questions/465099/best-way-to-build-a-plugin-system-with-java
http://en.wikipedia.org/wiki/Plug-in_\(computing)
http://twit88.com/blog/2007/10/07/develop-a-java-plugin-framework/
http://twit88.com/blog/2007/10/08/develop-a-java-plugin-framework-search-for-plugin-dynamically/