Service-oriented architecture (SOA) can be used for applications at any level. At its simplest, individuals can use Web-based office applications on Google. But SOA realizes its greatest potential in very large, complex installations that can't be done with older technologies. However, at this early stage in the technology's development, few organizations have the resources to attempt such projects, and those that do -- for instance, large financial firms -- consider their SOA applications to be competitive secrets.

One very large organization that does have the resources and that is public about its SOA development -- actually is required to be so by law -- is the U.S. federal government. A cross-agency group called the Federal Service-Oriented Architecture Community of Practice (SOA CoP) is developing what undoubtedly is one of the most ambitious projects yet attempted, nothing less than a single, intranet-based financial and HR system for the entire government, across all agencies and departments.