MMIL stands for "MultiModal Interface Language" and is intended to serve as a common language between modules in a dialogue system, typically involving natural language and other modalities.
About Interface Languages:
An interface description language (or alternately, interface definition language), or IDL for short, is a specification language used to describe a software component's interface. IDLs describe an interface in a language-neutral way, enabling communication between software components that do not share a language for example, between components written in C++ and components written in Java.
IDLs are commonly used in remote procedure call software. In these cases the machines at either end of the "link" may be using different operating systems and computer languages. IDLs offer a bridge between the two different systems.
Product's homepage