In this paper, we present a universal assistive technology with multimodal input and multimedia output interfaces. The conceptual model and the software-hardware architecture with levels and components of the universal assistive technology are described. The architecture includes five main interconnected levels: computer hardware, system software, application software of digital signal processing, application software of human-computer interfaces, software of assistive information technologies. The universal assistive technology proposes several multimodal systems and interfaces to the people with disabilities: audio-visual Russian speech recognition system (AVSR), "Talking head" synthesis system (text-to-audiovisual speech), "Signing avatar" synthesis system (sign language visual synthesis), ICANDO multimodal system (handsfree PC control system), and the control system of an assistive smart space.