James Clark announced an update of the TREX web site with refinements, and has created a complete implementation of XHTML modularization in TREX.

The only change made to the TREX language is a refinement to the way it handles merging included grammars.

Following hard on the heels of Murata Makoto's XHTML endeavors in RELAX, Clark has hand-crafted an implementation of the W3C's XHTML Modularization Candidate Recommendation in TREX.

XHTML Modularization decomposes XHTML 1.0 into abstract modules providing specific types of functionality. Clark writes of his implementation:

This has been done by hand not automatically, so there are probably bugs, but it takes full advantage of TREX. Notably, with TREX there's no need to create a model module specific to the combination of modules you are using; you just have to include the modules you need. I was also pleasantly surprised to discover that it was possible to implement exceptions in TREX (used in HTML 4 to, for example, prevent nested links), even though there's no specific exceptions feature in TREX.

Clark has added an explanation of the exception mechanism into his TREX tutorial.