jStates is a javalibrary for easy state machine design and implementation.It uses XML to define states and state transitions. jStates is aimed at easy integration with desktop J2SE applications, Struts, Commons Validator, Web and other J2EE technologies
nsjava is a loadable c-module which embeds a java virtual machine in aolserver. This module is being developed to support the openacs project - see http://openacs.org, but it could find general application as a web development tool.