HotMedia is a novel scalable solution for delivering interactive rich media over the Internet. It is a delivery-suitable file format that can contain heterogeneous compositions of media bit streams as well as meta-data that define the behavior, composition, and interaction semantics. This enables the creation of lightweight single-file representations of interactive, multiphase presentations involving multiple media-type content. The HotMedia client has a smart content algorithm that infers types from the incoming data stream and fetches the media renderer components, user-interface components, and hyper-linked action components, all just-in-time, resulting in progressive and contest driven enrichment of the user experience. Internet users get a simple initial experience with minimal latency followed by enrichment of this experience. HotMedia has an open and extensible architecture, which enables and encourages the inclusion of new media-types, user-interfaces, and hyper-linked actions. By separating media-rendering from action-performing, it lets all media handle the same actions. HotMedia can also track on the server-side, user interactions and user-experience associated parameters. In its simplest usage HotMedia requires no more than a regular web server for delivery and no client-side preinstallation.

A multi-user Virtual World has been implemented combining a flexible-object simulator with a multisensory user interface, including hand motion and gestures, speech input and output, sound output, and 3-D stereoscopic graphics with head-motion parallax. The implementation is based on a distributed client/server architecture with a centralized Dialogue Manager. The simulator is inserted into the Virtual World as a server. A discipline for writing interaction dialogues provides a clear conceptual hierarchy and the encapsulation of state. This hierarchy facilitates the creation of alternative interaction scenarios and shared multiuser environment.

Subimage motion in a three-dimensional computer graphic system is much easier for the user to control if the subimage moves the same direction as his hand while he manipulates the control device. The implementation of such coordinated motion of hand and subimage implies modification of the normal procedure for calculating transformations. The convenience of such manipulation also depends on appropriate selection or design of the input device.