Communication difficulties
Since XML preserves the structure of information, it provides a way of transferring data between different programs. There are advantages to going through one common format rather than having each pair of programs communicate directly with each other: each time you add a program to the pool the only work required is to make it read and write the standard format.
The alternative is that the newcomer must be able to read and write the format used by each of the existing programs, and so the effort involved increases with the number of programs. Using XML as a standard connector in this way is really just a special case--though an important one--of the more general idea presented in the previous paragraph.
Another consideration is that a document marked up with XML can be automatically and fairly easily translated to other markup languages such as HTML for the Web or WML for wireless. A single copy of a document (or the output from a single program) can thus be reused in different circumstances without modifying the original.
This isn't just a question of technical convenience. As a Fuji Xerox Australia white paper "XML for the Marketer" points out: "The separation of the information type from the style gives XML flexibility in its application. Once the data is approved through the internal compliance/legal/marketing departments the same data can be used in multiple formats with reduced risk to data integrity."
So it's not merely that XML can reduce the effort required to repurpose information for different delivery channels, but it helps ensure that identical content is delivered regardless of its format in each channel.
"The advantage is that XML provides separation of form and content...[or] structure from presentation," says Monash's Hurst.
