pdftl Notices

This software (pdftl) is distributed under the Mozilla Public License 2.0.

PDFtk Compatibility

CLI design

The pdftl command-line interface is a clean-room implementation intended to be compatible with PDFtk Server.

  • Original Concept & Design: Sid Steward

  • Implementation: This project is a clean-room implementation in Python. It does not use source code from the original PDFtk (GPL) or any other implementation.

  • Status: This software is not affiliated with or endorsed by the PDFtk project.

PDFtk is a trademark of Sid Steward and PDF Labs. This project is not affiliated with, endorsed by, or connected to PDF Labs.

Compatibility test suites

pdftk-java tests

The tests located in vendor_tests/pdftk-java are ported from the pdftk-java project.

  • Original Copyright: Marc Vinyals and the pdftk-java contributors.

  • License: These specific test files are licensed under the GNU General Public License (GPL) v2 or later.

  • Note: These tests are used for verification during development and are excluded from the binary distribution (wheel) of pdftl to preserve the permissive license of the core library.

php-pdftk tests

Tests from the php-pdftk project may be downloaded to vendor_tests/php-pdftk using scripts in tools/, to verify compatibility with php-pdftk. No files from the php-pdftk project are included in pdftl.

  • Original Author: Mike Haertl

  • License: MIT License

Artwork

The pdftl icon

The pdftl icon is a derivative work. It incorporates elements from the Google Noto Emoji library.

  • Original copyright: 2013 Google Inc.

  • Original license: Apache License, Version 2.0

  • Modifications: The artwork has been modified (recolored, reshaped, and combined) for the pdftl project.

  • Icon license: These modifications and the resulting composite icon are licensed under the Mozilla Public License 2.0 to match the pdftl project’s primary license.

Third-party components

OCRmyPDF

Portions of the optimize_images operation are adapted from OCRmyPDF.

  • Original author: James R. Barlow

  • License: Mozilla Public License 2.0

  • Copyright: © 2022 James R. Barlow

The original source code can be found at https://github.com/ocrmypdf/OCRmyPDF.

swapfont

Portions of the font replacement logic (specifically src/pdftl/fonts/font_{embedding,utils}.py) are adapted from swapfont.

pikepdf/qpdf

This project relies heavily on pikepdf (© 2022-2024 James R. Barlow, MPL 2.0) and qpdf (MPL 2.0). While not directly “adapted” code, they are core dependencies that make this tool possible.

pypdfium2 / PDFium

The dump_text operation and the flatten option use pypdfium2.

  • pypdfium2 Copyright: Copyright © 2021-2026 geisserml and contributors.

  • PDFium Copyright: Copyright © 2014 PDFium Authors (Google Inc.).

  • License: BSD-3-Clause / Apache-2.0.

  • Source: https://github.com/pypdfium2/pypdfium2