Anthony Finkelstein of University College London has announced the public availability of consistencycheck.com, a service which provides rule-based link generation and consistency checking.

Working in a similar vein to Rick Jelliffe's Schematron, Consistencycheck processes a collection of rules expressed in XML, and checks document instances against those rules.

It is available as an online application, requiring Java applets to be enabled in your browser. The web site provides comprehensive explanations and examples.

While the online checker is free to use, the underlying technology itself can be licensed for use in commercial products. Free use is offered to educational and research establishments.

Example applications of this technology given include product catalogs, customer relationship management, software requirements management. Consistencycheck have also made their business outline (PDF) available for interested parties.