Open-source PDF readers and editors

7 PDF readers and editors whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

1. Okular Grade B

   KDE document viewer for PDF, EPUB, DjVu, comic books and other formats, with annotations, form filling and digital signatures.

   GPL-2.0-or-later. Source code

2. Papers Grade B

   GNOME's document viewer for PDF, DjVu, TIFF and comic book files. It is the successor to Evince.

   GPL-2.0. Source code

3. PDF Arranger Grade B

   Desktop app for merging, splitting, rotating, cropping and reordering the pages of PDF documents through a drag-and-drop interface.

   GPL-3.0. Source code

4. Xournal++ Grade B

   Handwriting note-taking app that also annotates PDF files with pen, highlighter, text and shapes, with support for pressure-sensitive tablets.

   GPL-2.0. Source code

5. Zathura Grade B

   Minimal, keyboard-driven document viewer with Vim-like key bindings. PDF, PostScript, DjVu and comic book support comes from plugins.

   zlib license. Source code

6. SumatraPDF Grade C

   Lightweight reader for PDF, EPUB, MOBI, XPS, DjVu and comic book files on Windows, available as an installer or a portable app.

   GPL-3.0. Source code

7. MuPDF Grade D

   PDF, XPS and e-book rendering library from Artifex, with a lightweight viewer, command-line tools and bindings for Python, JavaScript and .NET.

   AGPL-3.0, with a commercial license available from Artifex. Source code

Compare all 9 PDF readers and editors, open source or not.