Platform neutral device protocol techniques are described in which functionality to customize device interactions through communication busses is made accessible through platform independent script-based infrastructure. Functionality provided by an operating system to manipulate standard protocols of a communication bus used to interact with a connected device is exposed as script-based objects. Script-based protocol definition files associated with connected device may be employed to customize device protocols for the communications using the functionality exposed through the script-based objects. A computing device may acquire a protocol definition file for a particular device in various ways and host the protocol definition file via a suitable run-time platform. Requests for interaction with the particular device may then be handled using the custom protocols defined by the hosted protocol definition file.