The definition of meta models and the editing of models are the base enablers for the transformation of models. As the results of such transformations can replace human written source code or similar artefacts this approach offers a great potential.
A new version of the standard for QVT Operational is in the making, but currently version 1.2 is up to date.
In addition to the official OMG specification further learning materials are scarce. On Eclipse QVTo Seite the few existing items are collected.
For German reading people the book of Siegfrid Nolte QVT - Operational Mappings Modellierung mit der Query Views Transformation is an option that I do recommend.
The OMG standard on "MOF Model to Text Transformation Language" in Version 1.0 von 2008 is not especially recent, but nevertheless up-to-date.
In the Eclipse universe an implementation of this standards exists: Acceleo
Those well-versed in Java will quickly come to grips with the QVTo syntax. The tooling of Eclipse QVTo is not quite as comfortable as JDT, e.g. a formatter is missing, but by and large it is quite decent. A real plus, from my point of view, is the metamodel explorer, that is independent of QVTo and very useful for working with EMF.