Embodied agents present ongoing challenging agenda for research in multi-modal user interfaces and human-computer-interaction. Such agent metaphors will only be widely applicable to online applications when there is a standardised way to map underlying engines with the visual presentation of the agents. This paper delineates the functions and specifications of a mark-up language for scripting the animation of virtual characters. The language is called: Character Mark-up Language (CML) and is an XML-based character attribute definition and animation scripting language designed to aid in the rapid incorporation of lifelike characters/agents into online applications or virtual reality worlds. This multi-modal scripting language is designed to be easily understandable by human animators and easily generated by a software process such as software agents. CML is constructed based jointly on motion and multi-modal capabilities of virtual life-like figures. The paper further illustrates the constructs of the language and describes a real-time execution architecture that demonstrates the use of such a language as a 4G language to easily utilise and integrate MPEG-4 media objects in online interfaces and virtual environments.