"Build today, rebuild tomorrow." For more than a decade, this has been the sobering reality most large and mid-sized enterprises confronted when they tried to tie new software into their existing information infrastructure. Dozens of IT professionals would labor over expensive middleware applications, laying thousands of lines of rigid code just to make the new applications talk to the established ones. When the next application landed on their desk, a few months later, they would repeat the process again, sometimes ripping out the code they just laid.

But these days, IT folk sing a slightly more hopeful tune: "Build today, reuse tomorrow."

Fueling this refrain is Web services. A way to deliver software applications over the Internet, Web services allows applications to communicate across platforms and programming languages.

If the concept sounds fuzzy, think of it as life before and after word-processing software. Before it, rewording a 1,000-page manuscript meant entirely redoing it or entirely redoing certain sections. After it, rewording was as easy as "click and drag" and "cut and paste."

The concept has caught on quickly with a number of IT software providers. Microsoft, IBM, HP and a host of other IT software, hardware and services vendors both big and small trumpet Web services as the little engine that could resurrect the bleached bones of enterprise IT spending in the coming decade. In the coming year, Microsoft alone will devote substantial capital to building Web services and Web service tools as well as to educating the marketplace. (Witness the new .NET advertising campaign: One Degree of Separation.) So the mad scramble has begun for positioning in this emerging market, but what are companies jockeying for?

The Promise of Web Services

At heart nothing more than a stack of protocols, Web services hold a great deal of promise to change not only how software is integrated, but also how business is conducted. Web services could change the future of application integration because Web services allow programs to communicate regardless of language or platform. Web services could usher in a new era in distributed computing because business units within large enterprises could operate their own Web services without messy overlap or exorbitant IT costs. And Web services could establish a new pattern of business process deployment because Web services tools will make authoring Web services easy enough for savvy business executives to do without loads of expensive tech help. So while the immediate focus is on technology, the long-term dividend is that web services will put business minds back in charge of their information infrastructures.

For those who dismiss this as pure hype, remember what two other protocols--HTTP and HTML--did to the way people live, work and communicate. A protocol and a language for structuring documents, HyperText Transfer Protocol (HTTP) and HyperText Markup Language (HTML) made the Internet possible. These two standards lowered the bar for publishing information or selling goods and services, at least, in theory, before the Internet gold rush pushed the bar back. The dot.com bubble may have burst, but the legacy of its enablers remains: a few clicks separate us from troves of information, goods and services. Up to now, however, the Web itself largely changed the way people access information and how they occasionally buy goods. Web services promises to change the way businesses conduct business with consumers and each other. Consider this hypothetical application of Web services.

As Easy As ABC-XYZ

XYZ Company, a fast-growing investment banking company, buys ABC Corp., a financial-services firm. Everybody describes the deal as a win-win proposition because the two companies complement each other from product lines to corporate culture to corporate governance. Integrating the operations of both companies should be a cinch, analysts say, for that very reason. But there is one catch: XYZ uses Microsoft's .NET architecture for its information backbone, while ABC runs Java Open Network Environment.

If the year were 1999, this would be an expensive hitch. Why? Java and .NET don't talk. To allow ABC's employees to access XYZ's substantial research, the new entity must hire a consulting firm, buy some expensive middleware and expand its IT staff to stitch the two sides together.

Fast forward to the present, and the problem transforms into an opportunity. Because IT software and services providers have rallied around a new Web-based standard called Simple Object Access Protocol (SOAP) 1.1. Introduced quietly in 2000, this deceptively simple approach for sending and receiving data by piggybacking it on the HTTP protocol offers an easier method for systems integration and the promise of much greater opportunities to come. "Suddenly Microsoft and non-Microsoft environments have a way to speak to one another that is reasonably low cost and reasonably easy to implement" says James Governor, principal analyst and IT advisor for Application Strategies and Enterprise Management at Illuminata, a technology market research firm. He operates out the Nashua, N.H. firm's London office.

Thus Web Services are born.