Ambassadr is an ambitious smart home project - involving automation, notification and control.
Home Assistant (HASS) is an Open Source, Python and YAML based home-automation platform with a significant number of community maintained components allowing for hardware integration and some really awesome software-level API work.
It runs on bi-weekly release cycles - for the sake of stability, Ambassadr is normally running on at least the .1 release (so is often about a week behind releases, unless there are urgent security updates in which case it's patched immediately).
I've been working on a full overview of Ambassadr for a long while now - it'll hopefully be in a position to be published soon!