List of Free code Framework Concurrency
CSP based concurrency framework for Java.
ESA (Event Sourced Actors.Modular). Light weight, modular, Java framework for creating highly concurrent programs.
n2io concurrent network applications framework.
Staged Server Framework
A framework that can be used to quickly build highly concurrent Java servers with a stage based architecture.
UML Statechart Framework for Java
The framework implements UML statecharts in Java. Next to the standard elements of FSMs, hierarchical and concurrent states are as well supported as pseudostates, segmented transitions, timed events and an eventqueue for dispatching events asynchronously.