I assume you mean you thought X10 and Zwave communicate via WiFi (802.11A/B/G/N/etc). That is not correct.
X10 communicates either through power line control (PLC) or via radio waves (RF). Zwave communicates via radio only (RF). In order to use these with a PC, you need a controller of some kind to interface with your chosen automation hardware. For X10, most users opt for the CM15A which does both PLC and RF communication (as well as working with X10 RF security protocols). For Zwave, you'd need some kind of controller, but I can't recommend anything as I don't use it. The one mvdarend recommended is probably as good advice as any!
Once you have the PC/Raspberry Pi hooked up to the controller, HG installed, and everything configured, you can then use HG to control your hardware.
I don't know what stage you are currently at, so I probably stated some things that are obvious. But, to be fair, you asked for 4yo answers.