Open Source JMS (Java Message Service) Implementations written in Java

• ActiveMQ - ActiveMQ is a fast open source JMS 1.1 provider and Message Fabric supporting clustering, peer networks, discovery, TCP, SSL, multicast, persistence, XA and integrates seamlessly into J2EE 1.4 containers, light weight containers and any Java application. ActiveMQ is released under the Apache 2.0 Licence
  
  Features
  fully supports JMS 1.1 and J2EE 1.4
  includes JCA 1.5 resource adaptors for inbound & outbound messaging so that ActiveMQ should auto-deploy in any J2EE 1.4 compliant server
  tested inside Geronimo, Spring and JBoss 4
  support for transient, persistent, transactional and XA messaging
  supports pluggable transport protocols such as in-VM, TCP, SSL, NIO, UDP, multicast, JGroups and JXTA transports
  supports very fast persistence using JDBC along with a high performance journal
  designed for high performance clustering, client-server, peer based communication
  REST API to provide technology agnostic and language neutral web based API to messaging
  Ajax to support web streaming support to web browsers using pure DHTML, allowing web browsers to be part of the messaging fabric
  Axis Support so that ActiveMQ can be easily dropped into Apache Axis runtimes to provide reliable messaging
  Spring Support so that ActiveMQ can be easily embedded into Spring applications and configured using Springs XML configuration mechanism
  can be used as an in memory JMS provider, ideal for unit testing
  Wildcard support to subscribe to powerful destination hierarchies.
  Composite Destinations support to allow many destinations to be used in one simple atomic JMS operation
  JSR 77 / 88 support for easy deployment & management & hot deployment
  provides an implementation of ActiveCluster
  
      
• Hermes JMS - Hermes is a Swing application that allows you to interact with JMS providers. Hermes will work with any JMS enabled transport making it easy to browse or seach queues and topics, copy messages around and delete them. It fully integrates with JNDI letting you discover administered objects stored, create JMS sessions from the connection factories and use any destinations found. Many providers include a plugin that uses the native API to do non-JMS things like getting queue depths (and other statistics) or finding queue and topic names
      
• JORAM - JORAM incorporates a 100% pure Java implementation of JMS (Java Message Service API released by Sun Microsystem, Inc.). It provides access to a MOM (Message Oriented Middleware), built on top of the ScalAgent agents based distributed platform.
  
  JORAM is an open source software released under the LGPL license.
  
      
• MantaRay - MantaRay is an open source, fully distributed, enterprise-grade messaging middleware product that was designed to address the dual problems of todays high traffic IT environments their continuously changing structure and the ever growing volume and size of the messages passing through them.
  
  MantaRay combines cutting-edge design concepts messaging system optimization and peer to peer architecture that have enabled the creation of technology that is much more powerful than existing messaging systems in terms of speed, scalability, reliability, affordability, flexibility, ease-of-use and deployment time.
      
• OpenJMS - OpenJMS is an open source implementation of Sun Microsystemss Java Message Service API 1.1 Specification
  Features:
  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
  Applet support
  Integrates with Servlet containers such as Jakarta Tomcat
  Support for TCP, RMI, HTTP and SSL protocol stacks
  Support for large numbers of destinations and subscribers
      
• Presumo - Presumo is an implementation of the Java Message Service API.
  
  Our goal is to provide an open source Message Oriented Middleware solution based on the JMS API with features not available in other JMS implementations and performance (in terms of message throughput) better, or at least equal to, proprietary solutions.
  
  The overall design is a scalable distributed architecture with an emphasis on the Publish/Subscribe messaging paradigm and server-side content based filtering.
  
      
• Somnifugi JMS - SomnifugiJMS is an implementation of JMS that works inside a single JVM to send JMS Messages between Threads. Somnifugi is particularly useful for isolating the awt Thread so that the user interface will stay lively, for decoupling calls to slower external resources such as database connections, and for speeding up implementations of generic JMS clients by placing decoupled JMS clients in the same JVM.
      
• UberMQ Open Source JMS - UberMQ is a clean room implementation of the Java Message Service specification. JMS is a part of the Java 2 Enterprise Edition. We wrote UberMQ because many of the established JMS vendors have turned their back on the core tenets of distributed computing: fast and simple.