Only the Professional Enterprise Edition and Professional Edition will include support for custom-defined schemas. According to Microsoft XML Architect Jean Paoli, XML schemas are collections of XML tags that define the elements of an XML document and therefore the structure of information. A custom-defined schema is an XSD file written by the company that uses it (or by a contractor hired by the company) in order to define the tags that company will use in its XML. XSDs are written by developers in development environments like Microsoft's Visual Studio .NET.
The Standard, Small Business, Basic and Student and Teacher Editions of Office 2003 will not support custom-defined schemas. Instead, they will ship with schemas ready-made by Microsoft, like WordML and SpreadsheetML.
"All the versions of Office 2003 will have support for what we call Native XML," Microsoft Office Product Manager Simon Marks said. "Native means a native file format of Office. In this case we have SpreadsheetML within Excel and a new one for Word, WordML. Both of these formats save files as XML."
Marks explained that WordML, for instance, is designed to save both the XML description of a document and the formatting of the text within (in other words, whether it is bold, italicized, indented, etc.). He noted that XML parsers on other formats should be able to deal with the XML content of WordML documents, but they probably won't be able to parse the formatting information. Oracle and SQL databases are another story entirely, and Marks said "You can easily put a WordML document into an Oracle database or a SQL database and it can come out the other end as a Word document."
But he also acknowledged, "We didn't create WordML to be an interoperable format."
Some have used this decision to make the case that Microsoft has pulled a bait-and-switch, scaling back support for XML while leading customers to believe that all SKUs would have those abilities.
But Marks said the decision to not include support for custom-defined schemas in four of the editions has nothing to do with scaling back support for XML in the product. In fact, he noted that even Office 2002 contains some support for XML. Instead, he said, Microsoft strove to bundle the various editions according to how customers would use them.
"A lot of it is really based around listening to what our customers want," he said. "Customers said they want to have more control over information. It's enterprise customers that are most likely to use this [XML] functionality and they are most likely to get anything out of it."
Microsoft has taken the stance that small companies aren't likely to make use of custom-defined schemas because an IT staff skilled in XML and familiar with the XSD specification is needed to write one, and that's a prospect that most small companies' IT budgets are not prepared to support.
He added, "Smaller companies don't want to pay for functionality they won't use. So in the Small Business Edition we included tools geared for them, like Business Content Manager. We were really trying to make sure that we were delivering the right tool to the right customer for the right price point."
Also, he noted that small companies which see a need for a custom-defined schema, or those that want to implement an industry-wide schema like ebXML, can buy Professional Edition licenses for just the people within the organization who need access to it. Or, if they only need one application with that sort of capability -- for instance if the employee only works with Word or Excel -- Microsoft gives customers the option of just purchasing a license for the professional version of that application.
"For the first time with Office, rather than the SKUs being about what type of applications you're buy, it is going to be about what makes sense to you as a customer," Marks said. "People will see value and will purchase those ones that are appropriate."