In the past twenty years, computers and networks have gained a prominent role in supporting human communications. This book presents recent research in multimodal information processing, which demonstrates that computers can achieve more than what telephone calls or videoconferencing can do. The book offers a snapshot of current capabilities for the analysis of human communications in several modalities – audio, speech, language, images, video, and documents – and for accessing this information interactively. The book has a clear application goal, which is the capture, automatic analysis, storage, and retrieval of multimodal signals from human interaction in meetings. This goal provides a controlled experimental framework and helps generating shared data, which is required for methods based on machine learning. This goal has shaped the vision of the contributors to the book and of many other researchers cited in it. It has also received significant long-term support through a series of projects, including the Swiss National Center of Competence in Research (NCCR) in Interactive Multimodal Information Management (IM2), to which the contributors to the book have been connected.