It seems like every month things change. Earlier this year Caterpillar announced they are switching from their own engines to Kubota engines on a lot of their smaller equipment (skid steers, small wheel loaders, mini-excavators for example). Last month Bobcat announced it is switching from Kubota engines to Doosan engines (Doosan is their parent) in skid steers starting in 2014 partly because Kubota couldn't give them an engine without a DPF so they developed their own although some say in part they were miffed at Kubota for selling engines to Cat. As for ECMs being proprietary, that is a pain if the machine had multiple interfaces. Can't deny that. Still I remember the first auto transmission car we had, a '51 Chev my dad picked up cheap, 2 speed Powerglide that took what seemed like a full second to make a shift. My main car now has an 8 speed of which I can't tell shifts unless I really stomp on it - and it gets triple the fuel economy of that '51, doesn't need new points, plugs, and condenser every 8,000 miles.