The Developer Certificate of Origin (DCO) is a statement that a software developer affirms when modifying the code of free and open-source software. Software distributed with a free and open-source license typically contains contributions from multiple intellectual property rights holders. Each contributor retains the copyright to their work while agreeing to license their modification to others under the terms of the original software license. The Developer Certificate of Origin is an attestation by the contributor that they are, or have been authorized by, the intellectual property rights holder to contribute the modification publicly.
The Developer Certificate of Origin was introduced in 2004[1] by the Linux Foundation as part of the submission process for software used in the Linux kernel after the SCO–Linux disputes.[2][3] A DCO identifies the person who claims to hold legal liability for specific lines of code, which could assign liability in legal litigation and may deter someone from submitting code likely to cause legal issues.
The Developer Certificate of Origin differs from a Contributor License Agreement (CLA) in that a CLA is a signed legal contract that typically requires a contributor to assign copyright ownership to a specific entity or to license their contribution to a specific entity with more permissive terms than the free and open source license the software is distributed under. Proponents of the Developer Certificate of Origin contend that it is a lower barrier to contribution compared to a CLA.[1]
For projects using Git version control, the attestation is a footer[4] in the commit message added by using the -s | --signoff command-line option.[5]
Developer Certificate of Origin
Version 1.1
Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
Developer's Certificate of Origin 1.1
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.
Notable projects using Developer Certificates of Origin
References
- ^ a b Ben Cotton (2018-03-09). “CLA vs. DCO: What’s the difference?”. Opensource.com.
- ^ Wired Staff (2004-05-24). “Linux: Whose Kernel Is It?”.
- ^ Torvalds, Linus (2004-05-22). “[RFD] Explicitly documenting patch submission”. Retrieved 2025-01-18.
- ^ “git-footers(1)”. commondatastorage.googleapis.com. Retrieved 2026-06-12.
- ^ “Git – git-commit Documentation”. git-scm.com. Retrieved 2026-06-12.
- ^ “DCO Sign Off”. cert-manager. Retrieved 2026-06-12.
- ^ “Contributing to GCC: DCO Sign-off – GNU Project”. gcc.gnu.org. Retrieved 2026-06-12.
- ^ “Developer Certificate of Origin (DCO)”. The Linux Foundation Wiki. Retrieved 2026-06-12.
{{cite web}}: CS1 maint: url-status (link) - ^ “Developer Certificate of Origin (DCO) – Pi-hole documentation”. docs.pi-hole.net. Retrieved 2026-06-12.
External links
- Developer Certificate of Origin website, with legal text