ISIS is a trilingual spoken dialog system in the stocks domain. It supports the three languages commonly used in Hong Kong (Cantonese, Putonghua and English), and serves as a test-bed for our research in various speech and language technologies. This talk presents the ISIS system with a focus on its several unique features. We use the CORBA middleware to implement a distributed architecture that supports interoperability across platforms. We incorporate KQML (Knowledge Query and Manipulation Language) software agents to handle delegation dialogs. We also implement a mixed-initiative dialog management strategy that combines online interaction with offline delegation. ISIS can automatically assimilate newly listed stock names into the system’s knowledge base. A recent enhancement supports multi-modal and mixed-modal input that suit the natural affordances of specific interactions in order to improve usability. Input modalities include speaking, typing or mouse-clicking. Output media include synthesized speech, text, tables and graphics.