The World Wide Web Consortium (W3C) today confirmed the fitness of several XML standards designed to query, transform and access XML data and documents.

XQuery 1.0, XSL Transformations (XSLT) 2.0, and XML Path Language (XPath) 2.0 passed muster as cornerstones for developing the Web with XML (define).

Connections between applications, databases, operating systems, Web services and Web servers have traditionally used middleware to convert data between the formats used by various applications. XSLT 2.0 and XML XQuery 1.0 will make those conversions, enabling users to focus on business logic.

XQuery 1.0 allows data to be mined from anything, including memos, Web services (define) messages and multi-terabyte relational databases.

The standard is expected to serve as a unifying interface for access to XML data, much as SQL has done for relational data, said Don Chamberlin of IBM's Almaden Research Center, who is co-inventor of the original SQL Query language and one of the co-editors of XQuery 1.0, in a statement.

Though the W3C is only now stamping its official seal of approval on XQuery 1.0, database makers IBM, Oracle  and Microsoft already support the standard in their database software.

Meanwhile, XSLT 2.0, which triggers the transformation and presentation of XML documents, adds new layers of functionality not found in its XSLT 1.0 predecessor, which is already used on Web servers and in browsers in some businesses.

XSLT 2.0 includes more facilities for grouping and aggregating data and providing more powerful text processing. XSLT 2.0 can also optionally use XML Schema, enabling improved detection of compiling and run-time errors.

Michael Kay, editor of the XSLT 2.0 spec, said in a statement XSLT 2.0 is a huge step forward in functionality and developer productivity, while also retaining a very high level of backwards compatibility.

XPath 2.0 is an expression language that allows the processing of values conforming to the data model defined in XQuery. XPath 2.0 supports a richer set of data types and takes advantage of the type of information that becomes available when documents are validated using XML Schema.

ZapThink analyst Ronald Schmelzer said XQuery, XPath and XSLT are core to manipulating data in the XML format and, as such, are core to making XML a long-term viability.

"But now that these are out, my guess is that they will make their way into products, and perhaps we'll see one or two more iterations before the pace of change dramatically slows," Schmelzer said.

"That's what happened to HTML after all. After version 4.0, who needs more?"