WSO2 WSAS packages a number of popular Apache Web services components. Seamlessly integrating these components in not a trivial task for a Web service developer. WSO2 WSAS takes this burden off the shoulders of the Web service developer and provides a clean and simple interface.
At the core of WSO2 WSAS is the popular Apache Axis2 Web services engine, which has proved to be one of the fastest Java Web service engines. Apache Axis2 has an extensible messaging engine architecture, which enables plugging-in of other quality of service modules (QoS). Apache Addressing, Apache Rampart, Apache Rahas and Apache Sandesha2 are such quality of service modules which are included in WSO2 WSAS. These QoS modules also seamlessly plug-in to Apache Axis2. These QoS modules implement the most popular and widely used WS-* standards; hence they have been prominently shown in the diagram. Needless to mention, security & relaibility are two essential aspects of any enterprise deployment. Rampart & Rahas provide implementations of WS-Security, WS-Trust & WS-SecureConversation. Sandesha2 is an implementation on WS-ReliableMessaging.
Apache AXIOM is the default XML Infoset representation used in WSAS. One of the reasons for the high performance of WSAS is the usage of a pull-based XML object model. Apache Neethi is the WS-Policy framework. In addition, WSO2 WSAS also bundles Apache XMLSchema which provides utilities for XML Schema manipulation, and Apache WSS4J, which contains implementations XML Security specifications as well as useful security utilities.