Open hardware¶

libdrone is released under CERN OHL-S v2. Not MIT, not Creative Commons, not "free for non-commercial use." CERN OHL-S — the strongest copyleft licence available for hardware. If you build on it, what you build is open too.

That was a deliberate decision, and it's worth explaining.

Why CERN OHL-S¶

Open hardware is harder to licence than open software. Code is unambiguous — the source is the thing. Hardware has a source (the design files) and a manufactured form, and the relationship between them isn't always clean.

CERN OHL-S v2 was designed by CERN specifically for hardware. It requires derivative works to be released under the same terms, defines "source" clearly for hardware contexts, and has been legally reviewed.

The reason to choose strong copyleft over permissive alternatives comes down to one question: what happens if a company takes the design, improves it, and closes the improvements?

With a permissive licence, they can. With CERN OHL-S, they can't. Improvements must be contributed back; everyone gets the benefit; nobody can privatise the commons.

What open hardware actually means¶

The design files are public. The full CAD source for every printed part is in the repository, every measurement in the variables file, every component choice explained in the hardware document.

Someone who has never met me can build this. No asking for files, no NDA, no waiting for a vendor. A printer, €250 in components, and the documentation.

That's what open means. Not "free to view." Reproducible.

The payload interface standard¶

The GX12-7 dual connector standard — the payload interface at the heart of libdrone — is documented as an independent specification. Anyone can build a payload for it without modifying the drone. The interface is stable; the drone is the carrier; the payloads are the point.

That's the decision that makes libdrone a platform rather than a project. One drone, any sensor. The interface is the product.

Full documentation at libdrone.eu.