Digital habitats is a framework for designing and modeling environments for activities that involve mobile and embedded computing systems. This paper 1) introduces the basic concepts of the framework, i.e. activity, thematic role, and the three ‘dimensions’ of a habitat: physical, informational, and pragmatic, 2) proposes a notation, and 3) sketches a method and exemplifies areas of application using authentic cases from hospital work, primary school education, the maritime domain, and other areas