Rick Jelliffe has announced the beta release 1.5 of Schematron, merging code from different implementations to provide a more open, flexible and powerful version of the rule-based schema language.

Schematron 1.5 uses the new architecture introduced with Schematron 1.3 and should be compatible with existing 1.3 schemas. New features include:

• Same version works with both namespace and non-namespace (Schematron 1.3 required 2 different implementations)
• Implements phases, diagnostics, inherited abstract rules, value-of
• Better compile-time error messages
• Extends the architecture to make available more attributes

The new release uses a "conservative subset of XSLT" and is still compatible with XT -- assuming schemas do not use keys (a XSLT feature not supported by XT). It also includes conformance tests and specifications to be used by further implementations of Schematron 1.5.

Discussing the need to add more features, Miloslav Nic thinks that Schematron has reached a stable point where the project needs to rest for a while:

I have feeling that the Schematron achieved the level of complexity which is needed just now. Maybe there should be experimental Schematron 2.0, but people have to have time to digest the current one.

The announcement comes while an active debate is being held on XML-DEV to compare the differences and synergies between the available XML schema languages.

Other story:

• Schematron for RDDL and RDDL for Schematron