Over the course of the last few months, I've spend some spare time for a new project:

howl is a web-based modular home automation software, written in python/django. Modules (sensors, actuators or interfaces) are added as django apps.

A ruleset can be defined to control interactions of modules (e.g. if sensor.livingroom.temperature drops below 15°C, send a notice via xmpp/email/... )

Nodes used in my setup are for the most part cheap arduinos, a kindle as a weather display and some remote controllable main sockets.

Source code is available on github under MIT license.

The software is provided  "as-is", without any claim of usefulness.