Apache ActiveMQ is an open source message broker written in Java together with a full Java Message Service (JMS) client. It provides "Enterprise Features" which in this case means fostering the communication from more than one client or server. Supported clients include Java via JMS 1.1 as well as several other "cross language" clients. The communication is managed with features such as computer clustering and ability to use any database as a JMS persistence provider besides virtual memory, cache, and journal persistency.ActiveMQ is used in enterprise service bus implementations such as Apache ServiceMix and Mule. Other projects using ActiveMQ include Apache Camel and Apache CXF in SOA infrastructure projects.Coinciding with the release of Apache ActiveMQ 5.3, the world's first results for the SPECjms2007 industry standard benchmark were announced. Four results were submitted to the SPEC and accepted for publication. The results cover different topologies to analyze the scalability of Apache ActiveMQ in two dimensions.