We are using ActiveMQ 5.2 as our implementation of choice and we picked it a while ago. It performs well enough for our use right now. Since its been a while, I was wondering what other Java Message Service implementations are in use and why? Surely there are more than a few.
Answer
Before delving into JMS, consider AMQP as well - might be a new standard. JMS providers I worked with (in varying degrees):
TIBCO EMS - very quick and robust, good API support, Java friendly, native C API exists. Best commercial choice I've used.
Websphere MQ (and its JMS implementation) - so, so. Pub/sub not exactly quick, many configurations options and choices are 'strange' and overly complex from the long history of that product. Just look at the amount of documentation...
Solace JMS - very high throughput (the JMS broker is built in hardware !), good choices of connecting protocols (MQTT, AMQP, XML over http as admin protocols)
Fiorano MQ - used to be agressive in marketing but lost a lot of market share, maturity concerns
Sonic MQ - solid product, also supports a C API
Active MQ - if you want to go with an open-source product (unexpensive support, great community, limited add-on products, limited enterprise features) this is probably your best choice. Works out of the box and is the backbone of several tools like Apache Camel, for example.