pyPdf-GUI is a Python-based graphical user interface for the pure-Python PDF library pyPdf, allowing the user to easily manipulate PDF files. It can extract pages, merge several files into a single one, rotate pages in a file, extract text, etc.
PS_View is a PostScript and PDF previewer. It is multiplatform (Windows, Linux and Mac OS X), GUI program based on the Ghostscript engine. Key features include huge magnification, fast viewing of large documents, exact measuring, and restart.