Rapid growth of competition on the electronic market place calls for innovative communication modes with web users. Considering the emergence of dynamic media objects containing temporal infromation such as animated character agents, web page scripts nowadays cannot satisfy users' increasing requirements well. We will develop a Dynamic Web Markup Language (DWML) as a software platform for authoring animated web pages with character agents. We assume that both primary media objects (text, image, etc.) and animated characters can be dynamic objects carrying time-based information, and that a character agent is a special dynamic medium as part of a multimedia interface. DWML, having a distributed structure and timeline ow, is used to generate both dynamic and static media objects, as well as characters' verbal and non-verbal behaviors.