Context-aware computing systems and methods are described. In some embodiments, hierarchical tree structures are utilized to ascertain a device context. The tree structures can be stored on or accessible to mobile computing devices so that the devices can determine their own particular context. A unique device architecture permits context aware computing and comprises, in at least some embodiments, a context service module, a common interface, and one or more context providers. The context providers provide information, through the common interface, that pertains to the context of a device, and the context service module processes the information to device the device's context.