OpenESB is a platform for business integration, Enterprise Application Integration, and SOA. OpenESB is 100% Open Source and is licensed under the CDDL.

OpenESB is built on an extensible core in which you can plug in components. OpenESB ships with a set of components not just for communication with back-end systems and other ESBs or SOA platforms, but also with components for document transformation, transaction processing, etc. Unlike proprietary ESBs, OpenESB is purely based on open standards. Components from any vendor that adhere to the JBI (Java Business Integration) and/or JCA (Java Connector Architecture) specification, can be plugged into the OpenESB core. This prevents vendor lock-in.

Other open standards supported by OpenESB, such as SOAP, WS-*, and miscellaneous XML standards, help with interoperability between OpenESB installations and installations of other ESB products or SOA platforms.

Part of OpenESB is an IDE that makes it very easy to create integration solutions or composite applications. This toolset is based on the Open Source NetBeans IDE.