Artifex Software
MuPDF
FreeView PDF documents with parser or rendering library.
WindowsAFPL Ghostscript
Freeengine for the interpreter for PostScript and PDF
MacSmartOffice - View & Edit MS Office files & PDFs
FreeSmartOffice is an intuitive, easy-to-use document editing application with a sleek design inspired by the familiar UI of a desktop Office document.
AndroidMuPDF for Linux
FreeAllow you to view PDF documents with parser or rendering library.
Linux