Homebridge is a lightweight NodeJS server you can run on your home network that emulates the iOS HomeKit API. It supports Plugins, which are community-contributed modules that provide a basic bridge from HomeKit to various 3rd-party APIs provided by manufacturers of "smart home" devices. Since Siri supports devices added through HomeKit, this means that with Homebridge you can ask Siri to control devices that don't have any support for HomeKit at all. Once your device has been added to HomeKit, you should be able to tell Siri to control your devices. However, realize that Siri is a cloud service, and iOS may need some time to synchronize your device information with iCloud. One final thing to remember is that Siri will almost always prefer its default phrase handling over HomeKit devices. For instance, if you name your Sonos device "Radio" and try saying "Siri, turn on the Radio" then Siri will probably start playing an iTunes Radio station on your phone.