Raining Sockets is a high-performance,
non-blocking, sockets-based framework.
Non-blocking IO (NIO or NBIO) allows one to create
thousands of connections in a single thread, thus
making applications highly scalable, compared to
the thread-per-client model used prior to JDK 1.4.
A user only needs to override the event that needs
to be customized, such as what to do with arrived
(or arriving) data, or what to do when a write has
completed. Raining Sockets has been tested
successfully with over 13,000 concurrent
connections.