Flexible user interfaces that can be customized to meet the needs of the task at hand are particularly important for real-time group collaboration. This paper presents the user interface of the DISCIPLE (DIstributed System for Collaborative Information Processing and LEarning) system for synchronous groupware along with the multimodal human-computer interface enhancement. DISCIPLE supports sharing of JavaBeans-compliant components , i.e., beans and applets, which at run-time get imported into the shared workspace and can be interconnected into more complex components. As a result, importing various components allows user tailoring of the human-computer interface. We present a software architecture for customization of both group-level and application-level interfaces. The application-level interface includes a management system for sharing multiple modalities across concurrent applications. This multimodal management system is loadable on demand yet strongly embedded in the DISCIPLE framework to allow a pervasive multimodal user experience. This creates a very flexible user interface, enabling the users to tailor it to their specific needs. Finally, we report the informal laboratory experience with the framework tested on a variety of applications and discuss its limitations.