A Variety of multimedia applications runing on different paltforms will need to communicate with each other particularly if they are running on a distributed network.
Until recently (and it may even still pose some problems) the lack of a common interchage file format was a serious impediment to development of a market of multimedia applications.
A common interchange format needs to be widely adopted (be supported by many applications) and be sufficiently experessive to represent a wide variety of media content. These may be conflicting requirements since only when a wide variety of media is suported will it be widely adopted. Propriety application on support a small variety of media they require and may not readily adapt to other formats. Fortunately some widely accept standard that support a wide variety of media (with open standards even) are now developed.
The need for interchange formats are significant in several applications: