OKF4net — a .NET implementation of the Open Knowledge Format (OKF)
Copyright 2026 Julien CHABLE

Licensed under the GNU Lesser General Public License, Version 3 or later
(LGPL-3.0-or-later). A copy of the license is provided in the LICENSE file
in this distribution (the LGPLv3 text), together with the GNU General
Public License, Version 3 in LICENSE.GPL-3.0, which the LGPLv3 incorporates
by reference as its base license. The licenses may also be obtained at
https://www.gnu.org/licenses/lgpl-3.0.html and
https://www.gnu.org/licenses/gpl-3.0.html.

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This project is a C# port of the Rust crate `okf`
(Copyright Walter van der Giessen, licensed under the Apache License,
Version 2.0), which was removed from this repository at commit d20343c
after byte-exact parity between the Rust crate and this C# port was proven
(see `tests/fixtures/`).

The Rust `okf` crate was itself a derivative of the Open Knowledge Format
(OKF) reference implementation:

    Open Knowledge Format (OKF)
    Copyright Google LLC
    https://github.com/GoogleCloudPlatform/knowledge-catalog

licensed under the Apache License, Version 2.0.

The attribution chain is:

    OKF reference implementation (Python, Copyright Google LLC, Apache-2.0)
      -> this repository's former Rust implementation, `okf`
         (Copyright Walter van der Giessen; removed at commit d20343c; Apache-2.0)
      -> OKF4net, this C# port (Copyright 2026 Julien CHABLE; LGPL-3.0-or-later)

Portions of OKF4net derived from those Apache-2.0 works — specifically the
concept-document parser/serializer, the concept-id/path conventions, and the
index-generation logic, ported from the OKF reference implementation's
Python `enrichment_agent.bundle` package (`document.py`, `paths.py`,
`index.py`) by way of the former Rust `okf` crate — remain subject to the
terms of the Apache License, Version 2.0, a copy of which is provided in
LICENSE.Apache-2.0. The OKF v0.1 specification (SPEC.md) authored by that
project is implemented here.

OKF and Google Cloud are trademarks of Google LLC. OKF4net is an independent
implementation and is not affiliated with, endorsed by, or sponsored by
Google.

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docs/spec/SPEC.md is the Open Knowledge Format specification (v0.2), copied
verbatim from okf/SPEC.md in the OKF reference implementation

    Open Knowledge Format (OKF)
    Copyright Google LLC
    https://github.com/GoogleCloudPlatform/knowledge-catalog

commit 62432a095456147ee71e70ac6e4dc0d2dea3ac30, licensed under the Apache
License, Version 2.0 (see LICENSE.Apache-2.0). It is vendored unmodified so
the normative text this project implements is available offline and at a
fixed version; see docs/spec/README.md for the provenance table and its
sha256. It is reference documentation only — no OKF4net library or binary
ships or reads it.

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bundles/acme_retail/ is a sample OKF bundle copied verbatim from
okf/bundles/acme_retail in the OKF reference implementation

    Open Knowledge Format (OKF)
    Copyright Google LLC
    https://github.com/GoogleCloudPlatform/knowledge-catalog

commit 3fcbb9f828c2f23d109c855ee403c3a4c81f3a96, licensed under the Apache
License, Version 2.0 (see LICENSE.Apache-2.0). It is fictional demonstration
content (a fictional company, "Acme Retail") used here for manual testing
and samples; see bundles/README.md for details, including which
upstream files were intentionally not carried over.

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bundles/ga4/ is a sample OKF bundle copied verbatim from
okf/bundles/ga4 in the OKF reference implementation

    Open Knowledge Format (OKF)
    Copyright Google LLC
    https://github.com/GoogleCloudPlatform/knowledge-catalog

commit 3fcbb9f828c2f23d109c855ee403c3a4c81f3a96, licensed under the Apache
License, Version 2.0 (see LICENSE.Apache-2.0). It documents Google's public
Google Analytics 4 obfuscated sample ecommerce BigQuery dataset; see
bundles/README.md for details, including which upstream files were
intentionally not carried over.

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The static site generated by `OKF4net.Viewer` (the `okf render` command)
embeds a vendored copy of marked v15.0.12

    marked
    Copyright (c) 2011-2025, Christopher Jeffrey
    https://github.com/markedjs/marked

licensed under the MIT License. The copy lives at
`src/OKF4net.Viewer/Assets/marked.min.js` with its original copyright banner
intact. It is used for client-side markdown rendering in generated pages only;
it is not a dependency of any OKF4net library or of the `okf` binary itself.