The Best PDF Viewer for LinuxLinux has quite a few PDF readers available, but Okular stands out as the best of the bunch, due to its ability to comment on, highlight, and otherwise annotate PDFs.
* View a number of different document formats, including PDFs, EPUB ebooks, CBR and CBZ comic books, DjVu, images, and more
* Annotate and mark up PDF files with comments, highlights, shapes, stamps, and more
* Extract text from a PDF to a text file
* Set bookmarks for later viewing
* Trim white page borders