Drop 4.a patent limitation from CC0

[TimidRobot]

Problem

CC0 1.0 is an excellent and popular legal tool for public domain software.

• In June 2016 an analysis of the Fedora Project's software packages placed CC0 as the 17th most popular license. (Public-domain-equivalent license - Wikipedia)
• Before 2022-08-01, Fedora recommended CC0:
  https://fedoraproject.org/wiki/Licensing/Unlicense:

  The "Unlicense" is similar to the Creative Commons Zero license, in that it is a legal construct intended to result in abandonment of any copyright where possible (and where not, license it under a permissive license similar to MIT). This is slightly different from a purely Public Domain work, because in some jurisdictions, the ability to place a work into the Public Domain is unclear. It is Free and GPL Compatible, whether the code is perceived to be in the public domain or under the permissive license terms.

  [NOTE: The first sentence of the following paragraph no longer reflects Fedora policy as of 2022-08-01, with respect to licensing of code]

  Fedora recommends use of CC-0 over this license, because it is a more comprehensive legal text around this tricky issue. It is also noteworthy that some MIT variant licenses which contain the right to "sublicense" are closer to a true Public Domain declaration than the one in the "Unlicense" text.

• It is the 2nd most popular Public-domain-equivalent license on public GitHub repositories (Quantifying the Commons 2025Q4 report)

However, the patent limitation in CC0 4.a has largely been rejected by the free/libre and open source software (FOSS) community

• CC0 4.a:

  4. Limitations and Disclaimers.
  a. No trademark or patent rights held by Affirmer are waived, abandoned, surrendered, licensed or otherwise affected by this document.

• Discouraged by the Open Source Initiative (OSI), Frequently Answered Questions:

  What about the Creative Commons “CC0” (“CC Zero”) public domain dedication? Is that Open Source?

  At this time, we do not recommend releasing software using the the CC0 public domain dedication.

  [...]

  [CC0 was not explicitly rejected [by the Open Source Initiative], but the License Review Committee was unable to reach consensus that it should be approved, and Creative Commons eventually withdrew the application. The most serious of the concerns raised had to do with the effects of clause 4(a) [...]

• Rejected by Fedora, [Fedora-legal-list] Change in classification of CC0 [LWN.net]:

  [...] We plan to classify CC0 as allowed-content only, so that CC0 would no longer be allowed for code. [...]

  The reason for the change: Over a long period of time a consensus has been building in FOSS that licenses that preclude any form of patent licensing or patent forbearance cannot be considered FOSS. CC0 has a clause that says: "No trademark or patent rights held by Affirmer are waived, abandoned, surrendered, licensed or otherwise affected by this document." (The trademark side of that clause is nonproblematic from a FOSS licensing norms standpoint.)

Description

Update CC0 and drop the patent limitation.

This would simplify the licensing landscape for authors who want their software to be completely open and ensure they can easily participate in programs like Google Summer of Code (GSoC) who require OSI acceptance.

Alternatives

Sadness 😢

Additional context

• Although OSI has blogged Public Domain Is Not Open Source (2017), they have approved other public-domain-equivalent licenses:
  • 2015: Zero-Clause BSD
  • 2020: The Unlicense
  • 2020: MIT No Attribution License
• Updating CC0 would benefit from other changes:
  • Degender legal text of CC0-1.0 #532