Free and open-source graphical interface for pdftk (PDF Toolkit), a command-line tool used to manipulate PDF files.
Create, edit, convert, and view PDF documents.
Free software for Windows that allows scanning and saving documents in PDF format.
Adobe Acrobat Reader allows you to view, comment, fill out, and sign PDFs on multiple platforms.
Free software to quickly and efficiently view, create, and edit PDF files.
Free utility to convert PDF files, extract texts from PDF files, in addition to many other features.