Ask HN: Architecture design for a mobile live streaming app (ex: Periscope)?

There seem to be many options for handling live streaming. From my research, popular protocols include RMTP, RSTP, HLS. Popular solutions include Wowza or Tokbox.

What are the key tradeoffs to consider regarding latency, cost, scalability, etc?

Are there any open source solutions?

What is the best way to integrate with a traditional backend (ex: Django) which will provide non-streaming data & logic?