How do I get a live stream of deltas from Meteor collection, for use outside of a webapp?
I'm looking for an initial result set, plus a series of operations on that result set, delivered as the happen.
The Meteor protocol is called DDP. It does exactly what you're asking for: you send a "subscribe" message that says what data you want to get, and then you get back the initial result set and then a stream of create/update/delete messages.
So what you need is a DDP client for whatever language the other program is written in. Since Meteor is so new, these don't exist yet. But a lot of people already written in to say that they want to write them. If you're interested in getting involved with that you should send a message to email@example.com.