Java plugin based web serverhttp://geronimo.apache.org/xbean/
XBean is a plugin-based server analogous to Eclipse being a
plugin-based IDE. XBean is able to discover, download and install
server plugins from an Internet-based repository. Support for
multiple IoC systems, support for running with no IoC system, JMX
without JMX code, lifecycle and class loader management, and a Spring
integration is included.