PDF Candy Desktop is a powerful multipurpose software that can convert from PDF, convert to PDF, compress PDF, OCR a PDF, merge PDF, split PDF, crop PDF, rotate PDF, unlock PDF, password protect PDF, extract images and text from PDF and more.
Gnostice Free PDF Reader is a free, fast, and portable application for viewing, printing and converting PDF documents. Free PDF Reader is a Java application. As a result, it can be used in Windows, Linux, and Mac (OS X).
Simple interfaces to some of the functionality of the excellent pdfpages for pdfLaTeX
pdftk is a simple tool for doing everyday things with PDF documents.