Open-Source Notices
Last updated: 25. 11. 2025
The P4PDF by Performance4 s.r.o. service uses open-source software components. We acknowledge and thank the authors and maintainers of these projects. Below is a non-exhaustive list of key components and their licenses.
iText 9
iText 9 is used for PDF processing and signing features.
License: GNU Affero General Public License v3.0 (AGPL-3.0)
Copyright © iText Software
Source and license details: https://itextpdf.com
BouncyCastle
BouncyCastle is used for cryptographic operations.
License: MIT License
Project site: https://www.bouncycastle.org
Entity Framework Core (including Sqlite & Npgsql providers)
Used for data access and persistence.
License: Apache License 2.0
Project site: https://github.com/dotnet/efcore
Stripe.net
Used for integrating the Stripe payment platform.
License: MIT License
Project site: https://github.com/stripe/stripe-dotnet
Testcontainers for .NET
Used for integration testing infrastructure.
License: MIT License
Project site: https://github.com/testcontainers/testcontainers-dotnet
Magick.NET (ImageMagick)
Copyright (c) Dirk Lemstra Licensed under the Apache License 2.0. https://github.com/dlemstra/Magick.NET
ZXing.Net
Copyright (c) Michael Jahn Licensed under the Apache License 2.0. https://github.com/micjahn/ZXing.Net
Source Code for P4PDF by Performance4 s.r.o.
As required by the AGPL-3.0 license for iText 9, the complete corresponding source code of the server-side software that forms part of P4PDF by Performance4 s.r.o. and communicates with users over a network is made available at: