Misterhouse

Some of the features I am looking for:

• Environmental monitoring
• Multiroom Audio
• Security
  

I would like to be able to control and monitor the environment with a touchscreen.

OK so MisterHouse, or maybe Pluto could be the ticket, it's GPL (free).

Other commercial packages look good Cinemar MainLobby at $179.99 has i-Pod Touch support, Calrad Xlobby, Homeseer (with Krumpy's plugin for expanded RS-232 support) and Promixis Girder.

Lots more research to do.