Okular
KDE document viewer with PDF annotation and form filling.
free offline open source
Get it →Offline & One-Time PDF Apps
PDF Arranger
Reorder, split and merge PDF pages with a simple GUI.
free offline open source
Get it →PDFsam Basic
Split, merge and rotate PDF files locally, free and open-source.
free offline open source
Get it →Stirling PDF
Free PDF toolkit with 60+ operations — desktop app or self-hosted.
free offline open source
Get it → Setup & migration guide → Free · pay what you want