2 Free and Open-source Pdf reader Apps for macOS (Intel and Apple Silicon)

1- FBReader

eBook reader for ePub, Mobi, ETF, and Fb2.

FBReader is a popular eBook reader that supports many eBook formats such as EPUB, Mobi, ETF, and fb2.

FBReader is not an open-source software, but it is avaiable for free for Windows, Linux, macOS, Android, and iOS.

FBReader uses its own book parser and rendering engine. The engine is lightweight, fast, and highly customisable.

Read about FBReader 's features, license, platforms, and more.

2- Skim

skimPDF reader and note-taking solution

Skim is a PDF reader and note-taker for macOS (10.7 and later). It's feature-rich program and very useful for researchers as it include notes, highlighting, bookmarks, editing tools and LaTeX support.

Read about Skim 's features, license, platforms, and more.