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CBF Licensing Guide

WARNING: This document is a work in progress and may be updated as the project evolves. It is intended to provide practical guidance on licensing policy for the CBF project, but should not be considered legal advice. For specific legal questions, consult a qualified attorney.

1. Scope

This document defines practical licensing policy for the standalone CBF repository. It is an engineering policy document and not legal advice.

2. Base License Choice

Recommended base license for CBF-authored code:

  • BSD 3-Clause

Why:

  • Permissive and widely acceptable for library reuse.
  • Consistent style with Chromium/CEF ecosystem expectations.

3. Layered License Model

Use a layered interpretation, not a single-license simplification:

  • CBF source authored in this project: BSD 3-Clause
  • Chromium and bundled third-party components: each component’s own license terms

Important implication:

  • Repository base license does not remove third-party notice obligations.

4. Redistribution Responsibilities

For source-only distribution:

  • Keep BSD 3-Clause license text for CBF code.
  • Document that Chromium/tooling dependencies are governed by their own licenses.
  • If the repository includes Chromium patch files or other Chromium-derived source diffs, include the Chromium license text alongside the repository (for example as LICENSE.chromium) and note that Chromium-derived portions remain subject to Chromium’s license terms.

For binary/distribution bundles containing Chromium artifacts:

  • Include third-party notices in release artifacts.
  • Preserve required copyright and attribution texts.

For example apps (Tauri/GPUI etc.):

  • Track app-specific dependency licenses separately from core CBF notices.

5. Release Bundle Files

For the current MVP pre-built macOS distribution, include:

  • Chromium.app
  • libcbf_bridge.dylib
  • CBF_LICENSE.txt
  • THIRD_PARTY_LICENSES.txt
  • SOURCE_INFO.txt

Optional supplemental artifact:

  • CHROMIUM_THIRD_PARTY_NOTICES.html

CBF_LICENSE.txt is copied from the repository LICENSE.

THIRD_PARTY_LICENSES.txt should be generated from Chromium with:

python tools/licenses/licenses.py license_file --format txt

CHROMIUM_THIRD_PARTY_NOTICES.html is human-readable supplemental attribution. It does not replace the required bundled license text.

6. Release Process Policy

The current release flow is local and manually invoked.

Recommended process:

  1. Regenerate THIRD_PARTY_LICENSES.txt from the exact Chromium revision used for the build.
  2. Generate SOURCE_INFO.txt from the exact tagged source state used for the bundle.
  3. Verify the release archive includes all required files.
  4. Manually upload the final archive after inspection.

See Release Process for the concrete MVP workflow.

7. Contributor/Consumer Clarity

README should state clearly:

  • CBF code is BSD 3-Clause.
  • Chromium/third-party components remain under their own licenses.
  • Redistributors must include relevant notices.

8. Compliance Checklist

Before release:

  • CBF_LICENSE.txt is present and matches the repository LICENSE
  • THIRD_PARTY_LICENSES.txt is generated for the exact Chromium revision being distributed
  • SOURCE_INFO.txt is generated for the exact tagged source state being distributed
  • Release artifacts include the required bundled license files
  • README licensing section matches actual distribution behavior

9. References

  • Chromium repository license page:
    • https://github.com/chromium/chromium
  • Chromium license tooling:
    • https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/licenses/licenses.py
  • Chromium OS licensing overview:
    • https://www.chromium.org/chromium-os/licensing/
  • SPDX BSD-3-Clause:
    • https://spdx.org/licenses/BSD-3-Clause.html