Notify is focused on sending server-side notifications to the client for applications building on hoplon and castra. The idea is to have a single poll loop (for now) and to send changes (in the form of notifications) rather than snapshots of server state. Notifications are sequenced and sent in batches; acknowledgements are for a given notification and for all prior notifications.
https://github.com/hoplon/notify
http://clojars.org/hoplon/notify
https://github.com/hoplon/demos/tree/master/castra-simple2