level of quality of service for SOA/WS/XML security applications. For SOA/WS/XML intermediary VTD-XML is well suited for SOA intermediary applications such as XML routers/switches/gateways, Enterprise Service Buses, and services aggregation points. All those applications perform the basic "store and forward" operations for which retaining the original XML is critical for minimizing latency. VTD-XML's incremental update capability also contributes significantly to the forwarding performance. VTD-XML's random-access capability lends itself well to XPath-based XML routing/switching/filtering common in AJAX and SOA deployment. Intelligent SOA/WS/XML Load-balancing and Offloading When an XML document travels through several middle-tier SOA components, the first message stop, after finishing the inspection of the XML document, can choose to send the VTD+XML file format to the downstream components to avoid repetitive parsing, thus improving throughput. By the same token, an intelligent SOA load balancer can choose to generate VTD+XML for incoming/outgoing SOAP messages to offload XML parsing from the application servers that receive those messages. XML persistence data store When viewed from the perspective of native XML persistence, VTD-XML can be used as a human-readable, easy to use, general-purpose XML index. XML documents stored this way can be loaded into memory to be queried, updated, or edited without the overhead of parsing/re-serialization. Schemaless XML data binding VTD-XML's combination of high performance, low memory usage, and efficient XPath evaluation makes possible a new XML data binding approach based entirely on XPath. This approach's biggest benefit is it no longer requires XML schema, avoids needless object creation, and takes advantage of XML's inherent loose encoding. It is worth noting that data binding discussed in the article mentioned above needs to be implemented by the application: VTD-XML itself only offers accessors. In this regard VTD-XML is not a data binding solution itself (unlike JiBX, JAXB, XMLBeans), although it offers extraction functionality for data binding packages, much like other XML parsers (DOM, SAX, StAX). Essential classes As of Version 2.11, the Java and C# versions of VTD-XML consist of the following classes: VTDGen (VTD Generator) is the class that encapsulates the main parsing, index loading and index writing functions. VTDNav (VTD Navigator) is the class that (1) encapsulates XML, VTD, and hierarchical info, (2) contains various navigation methods, (3) performs various comparisons between VTD records and strings, and (4) converts VTD records to primitive data types. AutoPilot is a class containing functions that perform node-level iteration and XPath. XMLModifier is a class that offers