Abstract: A computing device with an embedded microprocessor or micro-controller, including a software stack which comprises a content manager, and a runtime environment positioned in the stack above or together with a hardware abstraction layer. The content manager is not specific to any one design of runtime environment or hardware abstraction layer, so that several different designs of runtime environment and/or hardware abstraction layer can each operate with the same content manager. This de-couples the content manager from the runtime environment and/or hardware abstraction layer (e.g. a Java Virtual machine; elements of the operating system). The core advantage is that a single content manager can be used across multiple runtime environments and/or hardware abstraction layers; runtime environments and OSs can therefore be swapped without needing to re-write the content manager.