OBD GPS Logger logs OBDII and GPS data. It can then take that logged data and write useful output formats. Interesting information logged and exported includes how fast you're going, how fast the engine's going, the air flow into the engine, and the throttle position.
The very simple control protocol is a protocol for M2M (machine to machine), home automation, and similar things. This package includes programming tools, daemons, and userspace tools for using this protocol.