We have described a framework for mixed media that allows for the superposition of (text) dialogs delivered by humanoid avatars and/or speech balloons, on arbitrary rich media objects and virtual environments.

We have looked at the design space of mixed media presentations, by discussing a number of representative examples, each illustrating a particular level of complexity. Also authoring issues were discussed, and an indication was given of the style parameters needed to develop effective presentations.

We have further described the implementation platform used to realize the mixed media presentations and explored what new applications and extensions are feasible.