Skip to content

licensing.md

Latest commit

 

History

History
92 lines (71 loc) · 4.42 KB

licensing.md

File metadata and controls

92 lines (71 loc) · 4.42 KB

Licensing

LinSync is licensed as GPL-3.0-only. The repository root LICENSE file contains the GNU General Public License version 3 text.

Project Policy

  • GPL-3.0-compatible permissive licenses are allowed by default.
  • Copyleft dependencies are allowed only when their obligations are tracked.
  • GPL-2.0-only, AGPL, SSPL, Commons Clause, non-commercial, research-only, personal-use-only, unknown-license, and no-license inputs are blocked.
  • Third-party application source, assets, translations, bundled filters, and plugins are not copied into LinSync unless a later file-specific review proves compatibility with GPL-3.0-only.

The default source build must remain redistributable under GPL-3.0-only. Any non-free SDK, proprietary service, or unclear binary helper may only be documented as an optional integration and must not be required to build, test, package, or run the open-source application.

Dependency Classes

Permissive code licenses such as MIT, BSD-2-Clause, BSD-3-Clause, ISC, 0BSD, Zlib, libpng, BSL-1.0, Unicode-DFS-2016, Unicode-3.0, and Apache-2.0 are allowed through deny.toml.

Copyleft licenses that can be GPL-3.0-compatible, including GPL-3.0-only, GPL-3.0-or-later, LGPL-2.1-or-later, LGPL-3.0-only, LGPL-3.0-or-later, and MPL-2.0, require a dependency note before they are introduced. The note must identify the package, linkage/distribution mode, source-offer obligations, and whether the license has incompatible secondary-license terms.

Licenses that require case-by-case review before use include GPL-2.0-or-later, GPL-only Qt/KDE modules, EPL-2.0, CDDL-1.0, CDDL-1.1, OFL-1.1, Creative Commons asset licenses, helper binaries, OCR engines, PDF renderers, archive tools, and codec/media libraries.

Blocked inputs include GPL-2.0-only, AGPL family licenses, SSPL, Commons Clause, BUSL before its change date, PolyForm licenses, non-commercial licenses, research-only licenses, personal-use-only licenses, unknown licenses, and no-license code.

Qt And KDE

Qt and KDE components should prefer LGPL-compatible modules distributed in the normal system/Flatpak runtime model. GPL-only Qt/KDE modules require explicit review before use because they can change distribution obligations. KConfig may be considered later if it wins over the current JSON/XDG storage direction.

Qt WebEngine is not part of the default application shell. If webpage compare uses it later, it must stay feature-gated until licensing, security, sandbox, and binary-distribution obligations are reviewed.

Optional Helpers

PCRE2 is deferred unless Rust regex/fancy-regex cannot cover required legacy-compatible filters. If introduced, it needs a feature gate and license entry.

Archive support through 7z, libarchive, or other helper processes must document the exact helper license, whether the helper is bundled or discovered from the system, and how source/offers/notices are shipped. The current implementation decision is in docs/archive-support.md: start with system helper processes, keep the interface generic enough for a later libarchive-backed helper, and do not bundle helpers before review.

OCR engines, Poppler/PDF renderers, SVG/PDF/image renderers, codecs, and media helpers need explicit license and security review before becoming build or runtime dependencies. The shipped document/OCR compare paths use system-discovered helper processes (no new Cargo dependency); the design and helper review requirements are recorded in docs/document-compare-implementation.md.

Assets And Examples

Fonts, icons, screenshots, sample filters, sample plugins, fixture data, and Creative Commons assets need file-level provenance. Prefer project-created assets or assets with clear GPL-3.0-compatible terms. Do not copy third-party sample filters, icons, translations, plugins, or screenshots into LinSync unless a file-specific review proves the exact material is GPL-3.0-compatible. Current test fixture provenance is tracked in docs/fixture-provenance.md.

If legacy-compatible data files are ever imported, they must live in an isolated compatibility directory with attribution, license notes, and tests that prove LinSync does not depend on them for the default build.

Release Materials

The current source tree ships docs/third-party-notices.md with the Cargo dependency notices, source-offer notes, and copyleft dependency tracking status. Before each release, regenerate or review that file and verify the final package contents, not only Cargo manifests.