OpenXC is a non-production open source interface, designed to attract top developers to experiment with DIY projects in Ford vehicles (with or without SYNC); OpenXC is also an open-source hardware specification, so developers could design their own plug & play hardware modules, buttons, knobs & simple displays. The home for the OpenXC project on the web is http://openxcplatform.com.
The OpenXC vehicle interface is based on a microcontroller with two external connections – one to the CAN bus via the OBD-II port, and one to the host device via USB or serial. It passively listens for a subset of CAN messages, performs required unit conversion or factoring and outputs a generic version to the USB interface.
Unless you are implementing custom CAN messages, you will need a pre-built OpenXC binary from the manufacturer of your vehicle. The pre-compiled OpenXC vehicle interface firmware for Ford vehicles (required to get proprietary data streams) is available on this Developer Program page to developers that create an account and agree to the terms and conditions.