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Legal

This page documents the software licenses in use across the apps in this stack and the FOSS problems flagged for each.

Licenses​

Licenses fall on a spectrum from free to non-free. Free licenses grant use, modification, and redistribution rights. Non-free licenses restrict those rights in some way.

Free​

Public domain — Grants all rights with no conditions. The author has waived copyright entirely, or the copyright has expired. Equivalents like CC0 and the Unlicense achieve the same effect through a formal waiver.

  • Public Domain — Copyright waived entirely rather than licensed. No conditions at all — not even attribution — the most permissive position possible, one step beyond a permissive license granting rights under a copyright that still exists.

Permissive — Grants all use rights including the right to relicense. Anyone can use, modify, and redistribute the software, including in proprietary products. No obligation to share changes.

  • MIT — Preserve the copyright notice. Applies only to the covered code — your surrounding project can stay under any license.
  • Apache-2.0 — Like MIT, but adds a patent grant: each contributor grants users a licence to any patents covering their contribution, preventing them from later suing over it. Also requires attribution and noting modifications.
  • PostgreSQL License — PostgreSQL's own permissive license, predating and functionally equivalent to the MIT/BSD family — preserve the copyright notice, no obligation to share changes, no restriction on proprietary use.

Copyleft — Grants use rights but forbids proprietization. Weak copyleft stays contained to the covered files; strong copyleft extends to the combined work, making it incompatible with proprietary surrounding code.

  • MPL-2.0 — Weak copyleft. Only the original MPL-licensed files must stay open; surrounding proprietary code in separate files is permitted.
  • AGPLv3 — Running modified software over a network counts as distribution — you must publish your changes. The copyleft also extends to the combined work, so surrounding code linked with it must be open too. This closes the SaaS loophole in the GPL.
  • GPL-3.0 — Distributing the software — modified or not — requires publishing the source under the same license. But merely running it as a network service, without distributing the binary itself, doesn't count as distribution and doesn't trigger that obligation — the "SaaS loophole" AGPL was written specifically to close.
  • GPLv2 — The predecessor to GPLv3 — same strong-copyleft shape, distributing the software (modified or not) requires publishing source under the same license, but without GPLv3's explicit patent grant or anti-tivoization (hardware lock-down) provisions. No network-service clause either way; that's AGPL's addition, not GPL's.

Non-free​

Source available — Source code is published but under restricted terms. Commercial use that competes with the vendor is typically prohibited. The software is not free.

  • BSL 1.1 — Standardized by MariaDB in 2016 as a reusable template for source-available licensing. Publishes source code under restricted terms until a conversion date, after which it becomes open source (typically Apache-2.0). Each project fills in its own permitted and prohibited uses, so the practical restrictions vary.

Proprietary — Traditional copyright. No rights beyond what is explicitly granted. Source code may or may not be made available; redistribution and modification are generally not permitted.

  • EULA — No obligation to share source code — it may or may not be published. Terms of use are set entirely by the vendor and may change at any time. Redistribution is prohibited and production use typically requires an active subscription.

Trade secret — No information is made public. The source code is withheld entirely and its existence may not even be disclosed. The most restrictive end of the spectrum. No apps in this stack use trade secret protection.

Creative Commons​

Creative Commons licenses cover the same free-to-non-free spectrum as software licenses, but are designed for creative works — text, images, music, documentation. CC explicitly recommends against using them for software, where patent rights, linking semantics, and source distribution require dedicated software licenses.

The CC families map onto the same categories:

  • CC0 — Public domain equivalent. No rights reserved.
  • CC BY — Permissive. Attribute the author; do what you want with it.
  • CC BY-SA — Copyleft. Derivative works must use the same license.
  • CC BY-NC — Noncommercial. Free to use and share, but not for commercial purposes.
  • CC BY-ND — No derivatives. You can redistribute but not modify.
  • CC BY-NC-ND — The most restrictive CC license. Noncommercial and no derivatives.

The ND (No Derivatives) family has no software equivalent — restricting modification is incompatible with the concept of open source.

FOSS problems​

The table on each app page includes a FOSS problems column. Where an app has no known concerns, it shows "—". Where a problem is flagged, the label uses the concern names from isitreallyfoss.com/concerns. The ones that appear in this stack:

Not FOSS​

The software is not open source by any definition. Source code may or may not be published, but the license grants no meaningful freedoms — no redistribution, no modification rights, no right to run the software without a commercial agreement. Used by: Cloudron.

Open-Core​

The core product is open source, but meaningful features — typically SSO, API access, audit logs, or advanced integrations — are locked behind a proprietary commercial tier. Used by: Authentik.

Open Washing​

The code is published but under a license that is not OSI-approved open source. The Business Source License (BSL) falls here: it restricts competitive use and grants freedoms only after a delay. The intent is commercial protection, not software freedom. Used by: Dockhand, Docmost, Outline.

Copyleft License with CLA​

The project uses a strong copyleft license (AGPLv3) while requiring contributors to sign a Contributor License Agreement. This creates an asymmetry: contributors must release their changes under copyleft terms, but the company can relicense the combined work commercially without those restrictions. Used by: Nextcloud.