Last summer, IBM set up Power,org, to promote its PowerPC chip as what it called "open hardware." This year, Sun launched the OpenSPARC.net open source project around the source code for its Niagera microprocessor. But what does "open" mean in the context of hardware? In the case of Power.org, Juan-Antonio Carballo said, "It includes but is not limited to open source, where specifications or source code are freely available and can be modified by a community of users. It could also mean that the hardware details can be viewed, but not modified. And it does not necessarily mean that open hardware, or designs that contain it, are free of charge."
True to that statement, you have to pay to participate meaningfully in Power.org, as well as pay royalties to implement - it's built on a traditional RAND consortium model. To use the Sun code, though, its just download the code under an open source license, and you're good to go to use anything except the SPARC name. All of which leads to the questions: "What does "open" mean in hardware, and which approach will work?"