Apache ActiveMQ is an open source software which is the most popular and powerful messaging and Integration Patterns server. Apache is a message broker written in Java together with a full Java Message Service (JMS) client. It also enables to foster the communication from more than one client or server and this feature is commonly known as Enterprise Feature. Supported clients include "cross language" clients as well as Java via JMS 1.1. 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.

Niles Partners is launching a product which will configure and publish ActiveMQ, messaging server written in PHP for the MySQL database which is embedded pre-configured tool with LAMP and ready-to-launch VM on Azure that contains CMS Bundle, Apache, MySQL, Linux, PHP (LAMP).

Several modes of high-availability are employed, which includes both file-system and database row-level locking mechanisms, true replication using Apache or sharing of the persistence store via a shared file system. A robust horizontal scaling mechanism called a Network of Brokers, is also supported out of the box. In the enterprise, it supports relatively a large number of transport protocols, including OpenWire, STOMP, MQTT, AMQP, REST, and WebSockets and is also celebrated for its flexibility in configuration.

It is used in enterprise service bus implementations such as Apache ServiceMix and Mule. Other projects using ActiveMQ include Apache CXF in SOA infrastructure projects and Apache Camel.

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.

Some features of ActiveMQ are: