Stirling-PDF is a locally hosted web application that allows you to perform various operations on PDF files

diff-pdf is a tool tool for visually comparing two PDF files

Stirling-PDF — locally hosted web application that allows you to perform various operations on PDF files

marker — Convert PDF to markdown quickly with high accuracy

sumatrapdfreader is a PDF, eBook (epub, mobi), comic book (cbz/cbr), DjVu, XPS, CHM, image viewer for Windows. Fast, small, packed with features, customizable, free.