A computer implemented method for updating and distributing data objects among multiple client applications is described. The method includes receiving object data for an object from a first application instance of an application engine, wherein the object data reflects a change to a state of the object based on action of the first application instance, updating a data structure for the object in a based on the received object data, determining whether a transformation policy is applicable to the object and, if so, modifying data associated with the object according to the transformation policy, identifying application instances that should receive updated object data for the object based on stored information identifying clients that have agreed to share updated object data and based on stored information identifying types of updates that clients are to receive, and communicating updated object data to the application instances that should receive updated object data according to stored preferences associated with each of the application instances.