From Unimodal to Multimodal Interaction: Applications and Services Section II The second section of this book presents chapters describing problems faced when designing, implementing and using multimodal systems. These problems and their solutions are discussed considering specific modal and multi- modal applications. An example of solution for ambiguities is provided combining auditive and visual modalities; the problem of accessing objects and services supplied by multimodal mobile applications is faced by multimodal systems in different scenarios using Ontologies permitting interoperability between different environments and semantic interoperability for cooperation. The collaborativeness in designing interactive systems is discussed as a relevant issue to handle specific problems and face them on the field. Finally, the importance to make information and services accessible is highlighted, and one adopted solution for visually impaired people is described.