1. A context-aware system comprising: a computer configured to be mounted in a vehicle, the computer comprising one or more processors and computer-readable storage media associated with the one or more processors; one or more applications resident on the computer-readable media and configured to be executed on the one or more processors; one or more context providers operably associated with the computer and configured to provide context information; a context service module configured to receive context information from the one or more context providers and determine a vehicle context; at least one hierarchical tree structure resident on the computer-readable media and having multiple nodes each of which being associated with a context, the context service module being configured to determine the vehicle context by accessing the at least one hierarchical tree structure and traversing the at least one hierarchical tree structure, wherein individual nodes are uniquely defined by an entity identification that allows for discovery of accessible goods or services associated with that node, wherein the at least one hierarchical tree structure comprises: a first hierarchical tree structure having multiple nodes associated with a first context; at least one second hierarchical tree structure having multiple nodes associated with a second context, at least one node from the at least one second hierarchical tree structure being linked with one node on the first hierarchical tree structure by a link that is configured to enable a complete context to be derived from the first and second contexts; and a behavior engine operably associated with the computer and configured to, responsive to the vehicle context, adjust a behavior of the one or more applications so that the one or more applications behave in a manner that is consistent with a current vehicle context.