ActiveMQ
ActiveMQ Artemis
ActiveMQ's next generation of messaging
ActiveMQ 5.x
For a detailed instruction on how to migrate ActiveMQ 5.x to Artemis take look at the Migration guide
HornetQ 2.4/2.5
Existing HornetQ 2.4 and 2.5 clients will also be supported out of the box and also support all of the HA features, The caveat here is for UDP discovery which will need some manual configuration. The User Manual will have more details of this