msml

The Media Server Markup Language (MSML) is used to control and invoke
   many different types of services on IP Media Servers. Clients can use
   it to define how multimedia sessions interact on a Media Server and
   to apply services to individuals or groups of users. MSML can be
   used, for example, to control Media Server conferencing features such
   as video layout and audio mixing, create sidebar conferences or
  personal mixes, and set the properties of media streams. As well,
   clients can use MSML to define media processing dialogs, which may be
   used as parts of application interactions with users or conferences.
   Transformation of media streams to and from users or conferences as
   well as IVR dialogs are examples of such interactions, which are
   specified using MSML. MSML clients may also invoke dialogs with
   individual users or with groups of conference participants using
   VoiceXML.