This paper describes some details about the design of InTml, the interaction techniques markup language. We explain three main elements in its architecture: a simple mixed reality (MR) based component model, a communication model between components that allows fusion of multimodal information at a fine level of granularity, and an indirection mechanism for dataflows that is useful to keep state inside a dataflow. We also briefly discuss the advantages we have found in the use of formal methods, model driven development, and encapsulation mechanisms. The purpose of this description is to make explicit the design rationale of these mechanisms, which may be fruitful for other developments in our field.

This paper presents our research on the Interaction Techniques Markup Language (InTml). Our final goal in this work is to find ways to evolve and fit virtual reality (VR) applications over heterogeneous hardware platforms, a process we call retargeting. Toward this goal, we have developed a hardware-independent, component-based, formal model that describes the execution of VR applications; an XML language for describing complex and implementation-independent VR applications; a methodology for InTml-based development; a manual way to isolate and replace interaction techniques as a contribution to VR retargeting; and a set of tools for development support. This paper describes these topics and states future directions of our research.