XML Processing Model and Language Requirements published

Something new and intriguing has been published by W3C - XML Processing Model and Language Requirements.

This specification contains requirements on an XML Processing Model and Language for the description of XML process interactions in order to address these issues. This specification is concerned with the conceptual model of XML process interactions and the language for the decription of these interactions.

So in simple words it's a new XML language to describe XML processing. Say you want to get XML document out of Web Service, validate it, resolve XIncludes, XQuery some data and accordingly to the results apply some XSL transformation. Of course you can write custom application to do so (and keep doing so for each new XML processing scenario), but having XPL (or may be XPML) processor available you can just define the processing flow in XML document an run it. Cool. Similar to Apache Cocoon's XSP and BizTalk orchestrations.

Some teasing use cases:

Style an XML document in a browser with one of several different stylesheets without having multiple copies of the document containing different xml-stylesheet directives.

Apply a sequence of operations such XInclude, validation, and transformation to a document, aborting if the result or an intermediate stage is not valid.

Allow an application on a handheld device to construct a pipeline, send the pipeline and some data to the server, allow the server to process the pipeline and send the result back.

Norm Walsh is in editors, so I'm sure it's gonna be great new XML family member.