jQuery Lightbox - jQuery Lightbox plugins are utilized to showcase images and other web stuff using modal dialogs.
PDFTK Builder - PDFTK Builder is a free graphical interface to for PDFTK, making it much easier to use.
LightGallery - A modern, electron and nodejs based image viewer for Mac, Windows and Linux.
QPDF - QPDF is a command-line program that does structural, content-preserving transformations on PDF...
Fancybox - fancyapps.com - Fancy App Store
PyPDF2 - PyPDF2 - A utility to read and write pdfs with Python