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0002 — License under PolyForm Noncommercial 1.0.0

  • Status: Accepted
  • Date: 2026-05-15
  • Deciders: @sinidious

Context

CAESAR is built in the open as a homelab project. The author wants:

  1. Personal, hobbyist, and research use to be unambiguously allowed and friction-free.
  2. Commercial resale, hosted-as-a-service offerings, and white-labelling to be off-limits without a separate agreement.
  3. To keep the option of dual-licensing (commercial terms) without re-licensing everything later.

A permissive license (MIT/Apache) gives away (2). AGPL keeps source open but doesn't actually prevent commercial use, and its viral nature is hostile to integrating with non-AGPL ecosystems. Source-available licenses with a noncommercial clause hit the target directly.

Decision

CAESAR is licensed under PolyForm Noncommercial 1.0.0. A CLA (see ADR-0003) lets the maintainer offer the same code under commercial terms when needed without re-licensing.

Implications:

  • Personal, educational, and research use: allowed.
  • Commercial use of any kind: requires a separate commercial license from the maintainer.
  • Distribution must preserve the license notice (see NOTICE).
  • Dependencies must be compatible with PolyForm-NC distribution. MIT / Apache-2.0 / BSD / ISC / MPL are fine. AGPL / SSPL / GPL in shipped code requires an ADR and almost certainly will not be approved.

Alternatives considered

  • MIT / Apache-2.0 — clean, but allows commercial resale without any agreement.
  • AGPL-3.0 — protects against hosted-SaaS clones, but doesn't forbid commercial use and contaminates the dependency graph.
  • Business Source License (BSL) — time-bounded commercial restriction is interesting, but the 4-year flip to Apache feels premature for a homelab project that may pivot.
  • Proprietary / source-closed — defeats the homelab contribute-back goal.

Consequences

Positive

  • Clear "homelab welcome, businesses talk to me" signal.
  • Preserves the option of a commercial license without re-licensing.
  • Forces the project to be intentional about transitive dependency licenses.

Negative

  • Not OSI-approved; some contributors will not contribute on principle.
  • Some companies' open-source contribution policies block PolyForm-NC.
  • We must occasionally explain to users that "open source" and "free for commercial use" are not the same.

Neutral

  • The CLA (ADR-0003) is what actually enables future commercial dual-licensing; the license alone is not enough.

References