Discusses why MHEG can be considered as a key component in the design of open communication services. The focus is put on the global organization and architecture of multimedia services, and with respect to these architectural aspects, MHEG is a high level communication interface which enables application portability across a wide range of multimedia platforms. Objects and applications represented and encoded into the MHEG final form encoding are thus platform and hardware independent. MHEG can be viewed as a kind of “multimedia PostScript” for multimedia and hypermedia applications. This paper first presents a general introduction to the MHEG concepts. Then an overview of the basic requirements related to the interactive television (ITV) domain is introduced. The use of MHEG in this domain is detailed, showing how the generic specifications of the standard have been simplified and applied to the specific domain of ITV applications, with the definition of the MHEG5 profile in close collaboration with the DAVIC forum. The main assets of the MHEG standard are summarized with respect to the specific needs which arise in video on demand (VOD) and interactive TV services. (8 pages)