Most of us already have tools in the lab which emulate thermocouples, oscilloscopes, tachometers, and data acquisition devices. A few years ago, these were all hardware devices that resided in discrete boxes. Not only have the boxes disappeared, but in some cases, so have the boards and embedded processors which ran them. Still, there is the matter of who owns the protocols. Some creative software writers have found that even pure software plays are subject to royalty and license fees if proprietary protocols are implemented.
Some models are more permissive than others.
Well, if we listen to the marketplace, we see PC and software-based systems making substantial inroads into traditionally closed proprietary device markets. It has lots of good links to FAQs, history, opinion, mailing lists, and like-minded organizations.