I ntrod uction Problems with interoperability within the professional production environment have always been with us. Traditionally, there are the differences between 525-line and 625-line NTSC and PAL systems, and we have used expensive standards converters to move between the different scanning formats. With the move to digital, Recommendation 601, with its common "4:2:2" sampling structure and a common sampling frequency of 13.5 MHz, has been an immensely important foundation for the production industry. Today, compression is being applied in production to both the audio and video components because of the huge reductions this can bring in storage and networking costs. Unfortunately, this makes the interoperability situation worse because of the many different types and flavors of compression. If these compressed signals are stored as files on servers, then traditionally each manufacturer has their own proprietary format, making interchange of files between manufacturers nearly impossible. To add to this, program makers and broadcasters now want to exchange program metadata along with the video and audio, and this brings with it a whole new range of interoperability problems. It is very difficult to get different organizations to agree on a common metadata model and syntax, making exchange of metadata between databases very difficult without expensive, multiple translations between systems.