Open source Document viewers for Windows

MuPDF

The renderer in MuPDF is tailored for high quality anti-aliased graphics. It renders text with metrics and spacing accurate to within fractions of a pixel for the highest fidelity in reproducing the look of a printed page on screen. (GPL)

Windows

PDFCreator

PDFCreator is a free tool to create PDF-files from nearly any Windows application. (GPL)

Windows

PDFKeeper

PDFKeeper is a free, open source PDF document storage system that provides storage, indexing, and retrieval using the free Oracle Database Express Edition. (GPL)

Windows

PDFsam

PDFsam basic is a free and open source, platform independent software designed to split, merge and rotate pdf files. (GPL)

Cross-platform

PDFTK Builder

PDFTK Builder is a free graphical interface to the Windows version of PDFTK making it much easier to use. (GPL)

Windows

Sigil

Sigil is a multi-platform WYSIWYG ebook editor. Use Sigil to format and package your book into an EPUB. (GPL)

Linux - Windows - MAC OS X

Sumatra PDF

Sumatra PDF is a slim, free, open-source PDF viewer for Windows. (GPL)

Windows

7 applications