Various technologies and techniques improve the updating of client content in a client/server arrangement. A client notification engine of a user interface subscribes to receive notifications from a central server side notification engine. The client notification engine polls the server side notification engine at a specified interval. The server side notification engine receives and aggregates notifications about and/or from one or more sources and aggregates them into a collection of relevant notifications. These notifications are sent to the client where the different subscriptions originated and are then used by the user interface in the client to update part of the content being displayed as appropriate.