I've been focused on defining product strategy for business integration software for the past seven years. During that time I've watched XML go from being a fledgling document standard with lots of potential to a core technology that is critical for business integration. In this article, I'm going to discuss some of the reasons behind XML's meteoric rise in the business integration space and some of the ways we at IBM are leveraging XML in our integration products.

Why Has XML Become Central in Integration Products?
It's flexible: XML's ability to handle a diverse array of information formats and to readily transform data from one kind of document type to another makes it the perfect medium for integration. You can use XML for processing business documents that are simple in structure as well as for processing documents that are complex and highly structured. XML can also be used to query relational databases accessing sets of data in a rows and columns tabular format. It can then take the data, regardless of the source, structure, or format, and aggregate, transform, and ultimately render it in any format desired. This flexibility extends beyond data formatting and description. XML can be used to implement business rules as well as business process flow logic. These are all valuable characteristics for an integration solution that needs to mediate between many different data sources and destinations and must also enable business users to define business rules and logic that crosscut multiple applications and data sources.

It's pervasive and it's standards based: Perhaps the most obvious advantage is how pervasive XML has become. Today, XML is supported on just about every operating system in the marketplace. While broad availability is important to the success of most technologies, for integration, it's an absolute requirement. Integration is about hooking together disparate systems and people in a single coherent business process. It must, therefore, leverage technology that will be supported by whatever system(s) you communicate with on the other end of the wire. Open standards play a critical role in this. It's not enough that all participants support XML. All participating components in an integrated process, regardless of the vendor or developer that built the components, must understand the same vocabulary and implement the same grammar. Open standards provide us with these common vocabularies and grammars.

Business user acceptance and adoption: The driving force behind application and B2B integration is the need to optimize how you do business. Optimizing how you utilize IT resources is a secondary albeit valuable benefit. Consequently, IT and line of business users must work closely together on integration projects if projects are to succeed. Broad support for XML standards by tools for both IT users and for line of business users and XML's ability to render data and business process logic in formats suitable for both audiences have resulted in rapid adoption of XML technology by both audiences, which facilitates the cross communication successful integration projects require.

Almost all new industry-specific standards being defined for the purpose of integrating business partners are XML based. Line of business users are not only involved in defining these standards, they often are the driving force behind them. It is these standards bodies that define the common vocabularies and grammars that B2B integration relies on. Examples of some of these standards include UCCNET in the retail industry, HIPPA in insurance and health care, SWIFT and FIX in the financial services market, and RosettaNet in the technology industry. All of these standards leverage XML to some extent.

Many of IBM's customers have chosen to leverage XML in order to revitalize their EDI solutions rather than completely replace them. Why? Because they've got tremendous investment in the semantic content of those EDI transaction formats they defined with their partners. Why abandon those partner agreement formats while they are still applicable? The VANs, on the other hand, are often no longer cost effective. So our customers move their existing EDI transactions over to a TCP/IP-based platform in order to have the best of both worlds: leverage still-relevant transaction document formats along with the cheap pervasive technology of the Internet. What technology do they use as the data format bridge? You guessed it - XML.

How IBM Leverages XML
The WebSphere Business Integration technology stack nicely reflects XML's many uses in integration. Its use in our products is certainly pervasive. Our business integration products address a broad swath of integration needs including tight application-to-application integration, human workflow, and loosely coupled integration between business partners. Today, XML is the wire format most often used across our business integration technology stack. Our runtime components and all of our tooling leverage XML as a base technology for sharing information across components.

Our products also heavily leverage the many open standards that have been built on top of XML as well as XML's strength for describing both simple and very complex data structures. For example, all WebSphere Business Integration adapters, components whose job it is to connect to specific kinds of technologies and applications, use the open standard XML Schema, XSD, to describe the data format of the messages and events that they deliver and receive from the integration hubs they service. This is the case whether they are communicating with a process or a messaging hub. WebSphere Business Integration leverages the same XML standard for metadata description between our tooling and runtime components. Our native support for XML also makes our ability to support the many growing industry standards that much easier.

Moving Forward
Are there application areas or industries in which XML hasn't realized its potential? Without a doubt, although I don't know of a single industry that has not already or does not have plans to leverage XML for business process optimization. Some industries are further along than others, obviously, but all are moving in a direction to increase reliance on XML for sharing data with partners and customers. Nonetheless, XML still is characterized by having greater performance and processing overhead when compared to compiled application technology. IBM will continue to invest research funds to optimize its XML technology. An obvious example is developing ever more efficient XML parsers in order to minimize that overhead even further.

What are the most strategically important XML-based initiatives for business integration moving forward? I'd have to say Web services. The potential of Web services closely parallels that of XML - both are truly platform independent and both have or are gaining broad acceptance by the leading vendors. Thus Web services and XML have the same potential to be universally accepted - pervasive standards leveraged in all areas of the IT industry. It's not surprising that XML already plays a central role in Web services standards.