Putting files on the Web is not enough when you want to share hardware designs. Copyright law defaults to ‘all rights reserved’, and other IP rights are similarly restrictive, so designers need to provide certain freedoms to users explicitly. This is the role of licences.

Please refer to the introduction to copyright and licensing page in the documentation site of CERN’s Open Source Program Office (OSPO) for a short description of the three typical sharing regimes in open source: permissive, weakly-reciprocal and strongly-reciprocal. That site also contains good advice on the actual licences you can use in each of those sharing regimes.

Bear in mind that you project will typically include not only hardware, but possibly also gateware, firmware, software and documentation. Each part should be licensed under an appropriate open-source licence, and they do not need to be all the same. In fact, it makes sense to use a good hardware licence for the hardware, a good software licence for the software and so on.

Since this is the Open Hardware Repository, here you have, for convenience, links to the three variants of the CERN Open Hardware Licence (OHL) v2:

• The permissive variant, CERN-OHL-P-2.0 (txt, pdf). User guide (odt, pdf).
• The weakly-reciprocal variant, CERN-OHL-W-2.0 (txt, pdf). User guide (odt, pdf).
• The strongly-reciprocal variant, CERN-OHL-S-2.0 (txt, pdf). User guide (txt, pdf).

A good resource containing more detailed information, including licensing, is the Best Practices document from the Open Source Hardware Association (OSHWA).

If you have questions about the CERN OHL v2, or about open-source hardware licensing in general, you can post them in the CERN OHL v2 forum.