HomeSeer also uses Microsoft Speech technologies, both Speech Recognition (SR) and Text to Speech (TTS). You can check them out here.

Here’s what they say about themselves on their web site:

Home Automation Software & Systems for the Professional Integrator & Home AUtomation Enthusiast

Control lighting, security, HVAC and home theatre all from one central point with your PC. Access your PC via the web, your home
network, PDA, telephone or voice!