Digital content has been transforming from pure textual message to multimedia due to technical evolution of computer and networking, leading the development of object-based streaming MPEG-4 to interactive multimedia content. The progress of authoring methods from audio-video authoring to object-based scene authoring also ushers more multimedia content presenting devices. In this study, a scene-based document model and a multimedia authoring tool were constructed, under which the script language serves as the intermediate language between our authoring tool and MPEG-4. With the authoring tool, a multimedia authoring environment is created when combining the script language with MPEG-4. The visual tool provides a friendly environment for users who are unfamiliar with the grammar and syntax of XMT to create MPEG-4 content. Features of MPEG-4 players are being designed and will be developed for personal computers and handheld devices. Adopting component-based framework and was created in Java, the authoring tool supports higher portability in adding more functions to meet different demands.