There is an interesting read about an "open hardware" license here:
But I am interested in something that goes much further in several ways.
First off, my license would enforce the right and ability to modify a product and (especially) its firmware/software after it has been produced. This is what I mean by "open device" as opposed to simply "open hardware". In a world where the PC is increasingly pushed into a niche market, it is very important to protect the right to run software on other hardware, cell phones for example. I believe that the openness of the IBM PC is what created the personal computer revolution -- and why Apple lost out... as much as I love what Apple is doing on the physical side with the ipod, iphone, ipad, we need to ensure that Apple's restrictive policies do not prevail in devices or we will lose innovation in the personal device marketplace to the detriment of everyone who uses the devices.
This "modifiable device" restriction is also nice because it lets the original producer (and others) can use a high volume producer's hardware, so long as its functionality is accessible.. I believe that this would satisfy many open hardware developers since some are not motivated to make money; they are simply building a device that does not currently exist, and would be happy instead to buy it at Wallmart for significantly less cost. On the other hand, the greatest IP "theft" would be for a company to take a piece of open hardware and inaccessibly embed it within some consumer product, thereby reaping all the rewards of the open hardware communities' efforts and giving nothing back in return.
Secondly, I disagree with the TAPR's reliance on the GPL license to protect software, since (as I said above) it does not protect the ability to run that software on some device. It is very common for a company to comply with GPL by releasing the source of a Linux port onto a new CPU but in fact have no way for the end user to actually upload that release onto the CPU within the company's product! And generally other available hardware will not exist for the new CPU... Ironically, this effect is what drives some open hardware development, because the community then must produce (at great personal expense) custom hardware to utilize the Linux port...
There is one instance that I know of where in fact the software was released and the hardware fortuitously provided an update mechanism. This was the WRT-54G router. This device was a tremendous market success, and open source community's modifications to this router were so popular that some features were actually pushed back into the commerical release, AND even though the company eventually built a cheaper version on vxworks (a different operating system), they continued to sell the original under the product name WRT-54GL (more...). What if this phenomemon was the norm instead of the exception!?
Therefore, I believe that the hardware and software in embedded devices is intrinsically related -- one is almost worthless without the other. And finally, my experience as a software architect within the telecom industry and my experience as an open hardware developer is that in fact the software/firmware is 90% or more of the time effort. Since it is the major cost, it provides great leverage to pry off the lid of "closed" devices.
When you add these and a few other ideas together, you end up not with "open hardware", but something that looks a lot more like an "open device".