If you compare mailing lists, JORAM appears to be a much, much more stable product. If you compare features, ActiveMQ appears to be a lot more flexible in terms of what it can do, and how you can extend it.
The Joram team consistently reports that users usually don't grasp all Joram's capabilities at once. Apart from SOAP/J2ME access features, apart from bridge features with other JMS buses, Joram has interesting clustering, load balancing and high availability capacities.
Just quoting Joram's web site:
- A persistent, reliable and distributed JNDI server
- A configurable dead message queue
- Load balancing through clustered topics and queues
- Monitoring methods
- A bridge feature allowing to link JORAM to any JMS compliant messaging platform
- Client libraries allowing J2ME applications to access the JORAM platform in a JMS 1.1 "way"
- A graphical administration and monitoring tool
- High Availability provides the active replication of Joram servers and underlying agent servers, as well as replicated JORAM clients. It transparently handles network handover and server failover. This version currently relies on the use of JGroups.
- Dynamic Configuration, provides features to remotely add and remove Joram servers on the fly through the Administration API of JORAM. This great feature, combined with updated JMX implementation, initiates a new set of management facilities in Joram.