Domoticz is a great home automation software package which can easily run on a Raspberry Pi.

Domoticz can integrate into existing home automation hardware, some of these are: RFXCOM Transceiver, Z-Wave, P1 Smart Meter, YouLess Meter, Pulse Counters, 1-Wire, EnOcean, and a lot more. We have configured Domoticz to talk to the Belkin WeMo light switches as well as set up 2 x DS18B20 temperature sensors on a 1-wire bus (using GPIO pins of Raspberry Pi). MySensors is another great project which can be integrated into the Domoticz setup.