OpenXC is a hardware and software API for automobiles developed by Ford Bug Labs and proposed as an open standard.
At this time, the API is read-only (unlike the OBDII interface) and provides a small number of vehicle measurement parameters only (Engine speed, Vehicle speed, GPS position etc.).
A typical implementation uses the following architectural layers: Not all these layers are necessary, e.g. a vehicle might implement a native CAN Bus interface to USB or Bluetooth, without using the OBD socket or the reference OpenXC Vehicle interface Module.
The data available via the API as at January 2012 includes[7] Any information available from the current OpenXC API (and much more) is available from the OBD interface.
However the core OBD standard is concerned with the engine train, emissions and faults (much more data is available through custom PIDs) while OpenXC is focused on high-level instrumentation of more interest to a driver.