The WSO2 Enterprise Service Bus (ESB) is a fast, lightweight, 100% open source, and user-friendly ESB distributed under the Apache Software License v2.0. WSO2 ESB allows system administrators and developers to conveniently configure message routing, mediation, transformation, logging, task scheduling, failover routing, load balancing, and more. It also supports transport switching, eventing, rule-based mediation, and priority-based mediation for advanced integration requirements. The ESB runtime is designed to be completely asynchronous, non-blocking, and streaming based on the Apache Synapse mediation engine.

WSO2 ESB is developed on top of the revolutionary WSO2 Carbon platform, an OSGi-based framework that provides seamless modularity to your SOA via componentization. This release also contains many new features and a range of optional components (add-ons) that can be installed to customize the behavior of the ESB. Further, any existing features of the ESB that are not required in your environment can be easily removed using the underlying provisioning framework of Carbon. In brief, WSO2 ESB can be fully customized and tailored to meet your exact SOA needs.