Members of the open source hardware community publicly issued a list of standards that define a specific piece of hardware as open source. Among the signatures on the document were MIT Media Lab and Arduino lead software developer David Mellis, Adafruit founder Limor Fried, Creative Commons VP of Science John Wilbanks, and Wired editor and DIY Drones founder Chris Anderson.

There are eleven tenets to the open source hardware definition. From the definition:

1. Documentation

The hardware must be released with documentation including design files, and must allow modification and distribution of the design files. Where documentation is not furnished with the physical product, there must be a well-publicized means of obtaining this documentation for no more than a reasonable reproduction cost preferably, downloading via the Internet without charge. The documentation must include design files in the preferred form for which a hardware developer would modify the design. Deliberately obfuscated design files are not allowed. Intermediate forms analogous to compiled computer code -- such as printer-ready copper artwork from a CAD program -- are not allowed as substitutes.

2. Necessary Software

If the hardware requires software, embedded or otherwise, to operate properly and fulfill its essential functions, then the documentation requirement must also include at least one of the following: The necessary software, released under an OSI-approved open source license, or other sufficient documentation such that it could reasonably be considered straightforward to write open source software that allows the device to operate properly and fulfill its essential functions.

3. Derived Works

The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original hardware. The license must allow for the manufacture, sale, distribution, and use of products created from the design files or derivatives of the design files.

4. Free redistribution

The license shall not restrict any party from selling or giving away the project documentation as a component of an aggregate distribution containing designs from several different sources. The license shall not require a royalty or other fee for such sale. The license shall not require any royalty or fee related to the sale of derived works.

5. Attribution

The license may require derived works to provide attribution to the original designer when distributing design files, manufactured products, and/or derivatives thereof. The license may also require derived works to carry a different name or version number from the original design.

6. No Discrimination Against Persons or Groups

The license must not discriminate against any person or group of persons.

7. No Discrimination Against Fields of Endeavor

The license must not restrict anyone from making use of the hardware in a specific field of endeavor. For example, it may not restrict the hardware from being used in a business, or from being used in nuclear research.

8. Distribution of License

The rights attached to the hardware must apply to all to whom the product or documentation is redistributed without the need for execution of an additional license by those parties.

9. License Must Not Be Specific to a Product

The rights attached to the hardware must not depend on the hardware being part of a particular larger product. If the hardware is extracted from that product and used or distributed within the terms of the hardware license, all parties to whom the hardware is redistributed should have the same rights as those that are granted in conjunction with the original distribution.

10. License Must Not Restrict Other Hardware or Software

The license must not place restrictions on other hardware or software that may be distributed or used with the licensed hardware. For example, the license must not insist that all other hardware sold at the same time be open source, nor that only open source software be used in conjunction with the hardware.

11. License Must Be Technology-Neutral

No provision of the license may be predicated on any individual technology or style of interface.

Anyone versed with creative commons will find this list familiar. The full definition and full list of endorsers can be found at http://freedomdefined.org/OSHW.