Originally Posted by xsocket.sourceforge.net

xSocket is an easy to use NIO-based library to build high performance, scalable network applications. It supports writing client-side applications as well as server-side applications in an intuitive way. Issues like low level NIO selector programming, connection pool management, connection timeout detection are encapsulated by xSocket.

With xSocket you are able to write high performance, scalable client and server components such as SMTP Server, proxies or client and server components which are based on a custom protocol.