What is ESB? Today the IT world runs with several independent software components. Each components need to talk and communicate with each other in manner which can be understandable by other components. Some software components are still run on very old platform. At the meantime several new services are introduced to the IT world and that old systems need to incorporates with those services to achieve there business solution. And also the new concept, service-oriented architecture (SOA) needs an infrastructure that can connect any IT resource, whatever its technology or wherever it is deployed, to be flexible, it needs an infrastructure that can easily combine and re-assemble services to meet changing requirements without disruption. And to be dependable, it needs an infrastructure that is robust and secure. This infrastructure is Enterprise Service Bus (ESB). There are many ESB are available in the market. But, here my aim is to give some brief details about some Open Sources Enterprise Service Bus which are in Java. Apache ServiceMix Apache ServiceMix is an open source distributed ESB and SOA toolkit built from the ground up on the semantics and APIs of the Java Business Integration (JBI) specification JSR 208 and released under the Apache license. Mule Mule is a well known light-weight messaging framework. It is a highly distributable object broker that can seamlessly handle interactions with other applications using disparate technologies, transports and protocols. The Mule framework provides a highly scalable environment in which you can deploy your business components. Apache Synapse Apache Synapse is a easy-to-use and lightweight ESB which offers a wide range of management, routing and transformation capabilities. With support for HTTP, SOAP, SMTP, JMS, FTP and file system transports. Celtix Celtix delivers a Java enterprise service bus (ESB) runtime and set of APIs that make it easy to add transports, message formats, and security features. Open ESB Project Open ESB implements an Enterprise Service Bus (ESB) runtime with sample service engines and binding components. Open ESB allows you to easily integrate enterprise applications and web services as loosely coupled composite applications. WSO2 ESB The WSO2 ESB is an ultra fast, light-weight and versatile Enterprise Service Bus based on the Apache Synapse ESB. It allows you to Connect, Manage and Transform service interactions between Web services, REST/POX services and Legacy systems.. Petals Service Platform PETALS is an ObjectWeb project dedicated to deliver a Java(tm) Business Integration (JBI) compliant platform, providing lightweight and packaged integration solutions, based on JSR-208 specifications, with a high focus on distribution and clustering. ChainBuilder ESB ChainBuilder ESB is a new Java Business Integration (JBI) compliant open source solution for use in Service Oriented Architecture (SOA) environments. ChainBuilder ESB components are written in Java and easily configured via a graphical user interface plugged into the popular Eclipse development platform. jeeESB Jee(G)ESB is an JAVA Enterprise Service Bus. jeeESB will do Webservice Orchestration without any container or no need external containers. By a simple XML it will Webservice Orchestration. jeeESB is using XPath and XmlBeans for configuration.


Basically an Enterprise Service Bus (ESB) brings flow-related concepts such as transformation and routing to a Service-Oriented Architecture. And also an ESB can also provide an abstraction for endpoints. This promotes flexibility in the transport layer and enables loose coupling and easy connection between services.