Title: A Review of Context-Aware Architectures Computing devices have been evolving towards greater pervasiveness with the aim of becoming more user-centric. For example, laptops and handhelds have replaced traditional desktop computers to satisfy the need for mobile computing. The forthcoming era of Ambient Intelligence (AmI) envisions a world in which devices are embedded in the environment and work in concert to sense and respond to users' needs. Unlike traditional systems that require a user input to produce an output, AmI systems make use of sensors to collect context data, and reason upon this data to infer and react to meaningful events. Typical contextual cues include location, time, temperature, user presence and infrastructure available. Semantic web ontologies are a convenient technique to model context for different domains. In this talk, I will be speaking about different context ontologies and their supporting architectures.