In a session at XML DevCon 2001 in New York, XQuery working group members Jonathan Robie (Software AG), Michael Rys (Microsoft), Peter Fankhauser (GMD-IPSI), and Jérôme Siméon (Bell Labs) unveiled prototype implementations of the XQuery language. All four concluded that XQuery was relatively easy to implement, with work on three of the prototypes being started in November and finished by January.

The prototypes split along two distinct lines, with those from Software AG and Microsoft implementing the surface syntax and those from GMD-IPSI and Lucent implementing the query algebra.

The difference was explained by Paul Cotton, mediator of the session and chair of the XQuery working group. The surface syntax (which is what end users actually use) was not an initial priority for the group, who instead concentrated on the query algebra as a way to ensure that implementation issues would be well understood. The current surface syntax is derived from FLWR expressions in QUILT and does not exactly correspond to the query algebra. Aligning the two is one of the next tasks to be tackled by the group.

The Microsoft implementation of XQuery is available for use over the Web at http://131.107.228.20; the other implementations are expected to be available in the future.

Related stories:

• Avalanche of XML Query drafts
• XQuery, XSLT "overlap" debated
• XSLT 1.1 Cancelled, Working Group moving directly to 2.0