ESB

Apache Synapse
Apache Synapse is a easy-to-use and lightweight ESB which offers a wide range of management, routing and transformation capabilities. a wide range of management, routing and transformation capabilities. With support for HTTP, SOAP, SMTP, JMS, FTP and file system transports. Included is first class support for standards such as WS-Addressing, Web Services Security (WSS), Web Services Reliable Messaging (WSRM), efficient binary attachments (MTOM/XOP) as well as key transformation standards such as XSLT, XPath and XQuery. Synapse supports a number of useful functions out-of-the-box without programming, but it also can be extended using popular programming languages such as Java, JavaScript, Ruby, and Groovy.

Celtix
Celtix delivers a Java enterprise service bus (ESB) runtime and set of APIs that make it easy to add transports, message formats, and set of APIs that make it easy to add transports, message formats, and security features. The goal is to simplify the construction, integration and flexible reuse of technical and business components using a standards-based, service-oriented architecture.

Open ESB
Project Open ESB implements an Enterprise Service Bus (ESB) runtime with sample service engines and binding components. Open 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. This allows you to seamlessly compose and recompose your composite applications, realizing the benefits of a true Service-Oriented Architecture (SOA).

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 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. You can easily switch transports between http/s, JMS, File Systems, Mail etc, or read/write from Databases, split and aggregate messages and support declarative enforcement of QoS aspects such as WS-Security etc, and also switch between message formats such as SOAP 1.1/1.2, PoX/REST, Text, Binary, MTOM and SwA. It ships with a graphical management and administration console that allows easy configuration, development and monitoring, and an integrated Registry/Repository.

Petals Service Platform
PETALS is an ObjectWeb project dedicated to deliver a Java(tm) Business Integration (JBI) compliant platform, providing lightweight and Business Integration (JBI) compliant platform, providing lightweight and packaged integration solutions, based on JSR-208 specifications, with a high focus on distribution and clustering. PETALS leverages several ObjectWeb projects like Fractal and JORAM in order to provide a flexible and distributed ESB platform.

ChainBuilder ESB
ChainBuilder ESB is a new Java Business Integration (JBI) compliant open source solution for use in Service Oriented Architecture 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. ChainBuilder ESBs graphical Component Flow Editor creates the underlying JBI architecture, removing the burden of becoming a JBI expert in order to leverage the JBI standard. The Component Flow Editor provides a visual depiction of the entire integration environment allowing developers to step back and consider the flow of their application integration and then drill down on each component to define specific properties. ChainBuilder ESB also provides pre-built integration functionality, including industry standard editors to manage non-XML data formats, such as, EDI X12, fixed and variable formats.

JEE ESB
Jee(G)ESB is an JAVA Enterprise Service Bus. jeeESB will do Webservice Orchestration without any container or no need external 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.

Apache ServiceMix
Apache ServiceMix is an open source distributed Enterprise Service Bus (ESB) and SOA toolkit built from the ground up on the Service Bus (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. ServiceMix is lightweight and easily embeddable, has integrated Spring support and can be run at the edge of the network (inside a client or server), as a standalone ESB provider or as a service within another ESB. You can use ServiceMix in Java SE or a Java EE application server. ServiceMix uses ActiveMQ to provide remoting, clustering, reliability and distributed failover.