Matt Reimer's homebrew autonomous tractor uses open source components to accomplish the kind of automation that John Deere's super-proprietary tractors are known for.
John Deere infamously claimed that US copyright law prohibits any farmer modifications of their tractors, which would enable the farmers to gain access to the soil-density data that the tractor gathers as it plows. At present, that data is locked up in the tractor, and farmers can only access it by buying seed from John Deere's partners, Monsanto.
On CBC Radio One's Spark, Nora Young talked to Reimer about how he was able to use off-the-shelf parts to turn a "dumb" combine into a smart one, without having to be a literal tenant farmer, beholden to a multinational corporation that sees tractors as a platform and farmers as suckers. The hardware and software were transplanted from an autopilot from an open source drone.