We describe the design of an object-oriented multimedia database management system that can store and manage SGML/HyTime compliant multimedia documents.The system is capable of storing, within one database, dtrerent types of documents by accommodating multiple document type definitions (DTDs).This is accomplished by dynamically creating object types according to element definitions in each DTD.The system also has tools to automatically insert marhed-14~ documents into the database.We discuss the system architecture, design issues and the system features.Permission lo make digilnl/llnrd cop& ofnll or pn~t oftlk materinl for personal or classroom 11s~' is granted \vitllout Ike provided that the copies are not made or distributed I'or prolit or conuncrcinl ndvnnlagc, IlIe copyriglit notice.the lille ol'll~e publicnlion and its date appear, and notice is given La1 copyright is lay permission ol'thr ACM, Inc.To copy otherwise, lo republish.lo post 011 servers or lo redistributt lo lists.requires specific permission and/or fee.