The OpenJMS project was started by Jim Alateras and Jim Mourikis. It is sponsored by The ExoLab Group. OpenJMS was developed to the JMS 1.0.2 specification and supports both the pub/sub and p2p JMS messaging models. OpenJMS is currently in development but its source code is freely available and can be used in testing and learning about JMS. Obviously, the final version will be more complete. The server and clients are written in Java and can run on any platform with a Java 2 Virtual Machine. OpenJMS is based on a centralized hub-and-spoke messaging architecture. Clustering is not currently supported, so scalability and load balancing are limited to a single server instance.

Persistent messages are supported through any relational database that can be accessed with JDBC. Only local transactions are supported, so OpenJMS cannot participate as a resource in a two-phase commit. OpenJMS does not currently support firewall tunneling or any level of authentication or access control.

In the final release, clustering will be supported through a server-to-server communication protocol. OpenJMS will also support IP multicast and the HTTP 1.1 protocol, two-phase commit (as a XA resource), firewall tunneling, and security services such as authentication and access control.