An operating system for a computing device comprises a kernel portion having a publish and subscribe facility for retrieving a property published by a first process and notifying the retrieved property to one or more further processes requesting to subscribe to that property. By providing the publish and subscribe mechanism within the operating system kernel, changes to properties can be notified to subscribers in real time and without the need for dedicated client server mechanisms. The publish and subscribe mechanism may be provided with access control properties established when a property is defined. The mechanism may also be used for a message and message queue facility in the computing device.