Emerging multimedia technologies will allow users to store, retrieve, share and manipulate complex information in order to build exciting multimedia applications. Key challenges in the development of multimedia database systems include: content analysis of images and video data; knowledge-based representation of multimedia data; semantic modeling of events of interest and management of spatio-temporal metadata; facilities to retrieve multimedia data containing contents of interest to users; and design and development of high-performance multimedia database servers for networked environments. Multimedia systems must exhibit high degrees of robustness, efficiency and reliability for deployment in real-world environments.