The drive for user-entri systems in ombination with an emergen e of wireless networkings networking and increasing computing capabilities of mobile devices propel the development of Context-Aware (CA) systems. Moreover, nowadays, for the development of computer systems, the Service-Oriented Computing (SOC) paradigm became popular as it advocates use of services to support the development of rapid, low-cost, interoperable, evolvable, and distributed applications. Being a system development paradigm, the SOC can provide fundamental building blocks for developing ubiquitous CA systems. However, context-awareness itself is a relatively new and scattered research area. Due to the complex challenges encountered in a development of CA systems (such as context acquisition or the multifaceted nature of context), current research initiatives address only some specific problems, abstracting from others. Nevertheless, a holistic view of context-awareness encompasses numerous relevant cross-cutting research and development aspects. This holistic view is presented by means of a domain model of context-awareness proposed in this chapter. We reveal state-of-the-art of the individual research (sub-) domains and we analyze how they fit in the proposed domain model and how they map onto the widely used layered model for C A systems development. SOC could be effectively used to develop services catering to each (sub-) domain and SOC fundamentals such as interoperability and service composition could be further exploited to develop a complete CA system. This is shown in a case study of the Amigo project. Therefore, the contribution of this chapter is multifold. It provides a domain view of context-awareness to.