I had an X10 setup too, and it was great. I was just a teenager, so my ability to control the "whole house" was limited. But I had several of those relay-based

I had an X10 setup too, and it was great. I was just a teenager, so my ability to control the "whole house" was limited. But I had several of those relay-based switches and dimmers too, for the lights. I had an RF controller and the timer that was like an alarm clock. I always wanted the system you could install on a PC with DOS. I believe you could design a program and then upload it to an autonomous controller. X10 was exciting and unusual. It works by sending coded pulses through the household AC mains themselves. You have to set a "building code" in case your neighbors use X10, too, and their electrical system is closely coupled to yours. But obviously, it does not rely on the Internet, nor sends anything very far. I believe that once they hit a transformer, the code pulses will be neutralized.