SenseWeb is an open hardware platform for the rapid prototyping of embedded interactive systems. It is based on a modular architecture with various kinds of boards that can be stacked on top of each other in order to form the desired system. There are four categories of boards: I/O boards, processing boards, communication boards and integrated boards that combine several functions. Based on DSP’s, the processing boards can handle multimodal signals, such as audio, video, and any kind of sensors data. SenseWeb provides a comprehensive approach to the rapid prototyping of interactive systems and applications, starting from the streaming of signals into the PC for the development of new signal processing algorithms, until high level programming of stand-alone applications for interaction designers.