What does it take to make a robot tractor? A batch of free software, some drone parts, a tablet computer, and one curious farmer to cobble the bits together. Forget theory and gimmicks, robots are already operating on farmland. Matt Reimer's remote control 7930 is proof in the dirt. Working in his Killarney, Manitoba, shop with computer and hammer, Reimer, 30, has kicked open the door for autonomy in agriculture. He's done it on a shoestring budget and left a paper trail for others to follow. Rise of the machines is rather the rise of the open-sourced farmer.