JActor

JActor is a high-throughput Java Actor framework, Actor implementations in any language. Features include two-way messages to provide implicit flow control for performance under load, a simple machine builder is included to help keep application code clear and simple, can create more actors a second on a single thread, and continuations are context free and can be used to send a response back from any thread. It is ideal for making actors completely transparent to application code.

Requirements:

Java 6 and slf4j