The JMS API definies a java interface and an architecture for messaging, it does not define any specific wire protocol, it could be a carrier pigeon, in memory or any of the common formats (STOMP, OpenWire, AMQP, MQTT).
Why can't you use Open MQ libraries instead in your client? This is the way JMS is designed. You should only have to switch from the .jar files and change the ConnectionFactory
.
I don't see any reason to switch to ActiveMQ just for the sake of using the ActiveMQ JMS client, since it should be pretty much the same thing as the Open MQ client. There are other reasons to switch though, such as different server side features and what not, but you did not mention that.
That said, there is bridge component that is able to expose any JMS server over the STOMP protocol (which ActiveMQ supports).
It's called Stomp Connect and there are some rather old instructions at the OpenMQ page how to use it.
From there, you should be able to connect with ActiveMQConnection factory specifying STOMP. But I have not really tried this combination myself.