QVT nears completion

I'm off to Athens tomorrow to attend OMG, where myself and my cosubmitters will be presenting our (hopefully) final version of the merged MOF Query/View/Transformation spec.

QVT has become a bit of a misnomer, as Queries are dealt with by OCL expressions, and Views are not dealt with at all. Transformations, however, come in 3 favours:

Relations - the user-friendly declarative language, with patterns and templates and implicit traces between models,

Core - the lower level langauge which Relations map to, but which has the full semantics for multi-directional, incremental update, create and delete transformations. It is a thin layer above EMOF and OCL.

Operational Mappings is a set of extensions to OCL that have side effects, and provides a n "imperative" langauge for the transformation of models, which relies on the implicit trace generation of the Relations part.

Also, there's a way to use MOF operations to plug in black box implementations of any given Relation. This is viewed by some as a cop-out that destroys portability, but by others as a god-send that allows them to reuse libraries and algorithms that would be painful or impossible to re-express in one of the languages above.