Open Source JMS

1. Open Source JMS
   OpenJMS is an open source implementation of Sun Microsystems's Java Message Service API 1.0.2 Specification. Features include:
   * Point-to-Point and publish-subscribe messaging models * Guaranteed delivery of messages * Synchronous and asynchronous message delivery * Persistence using JDBC * Local transactions * Message filtering using SQL92-like selectors * Authentication * Administration GUI
   * XML-based configuration files * In-memory and database garbage collection * Automatic client disconnection detection .
                                                   
2. Open Source JMS Implementations
   JMS4Spread is a messaging system that partially implements the Java Messaging Service (JMS) API. JMS4Spread utilizes the Spread toolkit, a high performance group communication and message bus system that is resilient to faults across external or internal networks. JMS4Spread implements messaging in a completely distributed fashion so that there is no central server that represents a single point of failure. Each Spread daemon maintains a replicated state of the currently active topics via Spread groups. Currently, JMS4Spread supports non-durable messaging using JMS Topics and the Message Types: Byte, Stream, Map, Text and Object. JMS4Spread is being actively developed as a open source project at the Center for Networking and Distributed Systems, Johns Hopkins University.
   
   
3. Introduction to JMS
   JMS Overview Messaging is a method of communication between software components or applications. A messaging system is a peer-to-
   peer facility: a messaging client can send messages to, and receive messages from, any other client. Each client connects to a messaging agent that provides facilities for creating, sending, and receiving messages. a critical system broadcasts a signal that lets other systems know it is still working. You can apply the same concept between distributed Java components using JMS (Java Message Service). This article shows you how and introduces an extensible framework for implementation.