Why the Classic Windows PDF Patcher Is Now Open‑Source: Features, Code, and a Conscience License

If you’re looking for a veteran Chinese Windows PDF utility, the multi‑function PDF toolbox “PDF Patcher” (PDF补丁丁) has finally been open‑sourced (excluding third‑party components) on GitHub at https://github.com/wmjordan/PDFPatcher.

The tool offers a wealth of PDF processing functions:

Modify PDF attributes, size, page numbers, etc.

Handle PDF bookmarks (edit, auto‑generate).

Parse and extract PDF content (lossless image extraction).

Explore PDF document structure.

Create PDF files.

Split/merge PDF files.

Convert PDF files.

…and more.

Originally free but not open‑source, the software—over a decade old—has now been officially released as open source, sparking excitement from longtime users.

The author, @wmjordan, began development in 2009 and has maintained the project for more than ten years. In just a month, the repository has garnered over 3200+ stars and numerous issues, discussions, and feature requests.

The source code is primarily written in C# and C, reflecting its nature as a Windows .NET Framework graphical tool.

PDF Patcher relies on the .NET Framework and incorporates two open‑source libraries: iText (a .NET component) and MuPDF (written in C). The author provides the recommended development environment:

Windows 10, Visual Studio 2019

Workloads: .NET Desktop Development, C++ Desktop Development (with Windows 10 SDK)

One notable aspect of the project is its “Conscience License,” which adds two charitable clauses:

Users who benefit from the software should perform a good deed each time they use it.

If you develop a new software from the source code and profit, you must donate at least one‑per‑thousand of the earnings to vulnerable groups in society.

The author’s heartfelt approach reflects a programmer’s ultimate romance.