PDF-XChange Editor - The smallest, fastest, most feature-rich PDF editor/viewer available
Bullzip PDF Printer - Free PDF Printer - Create PDF documents from Windows applications. Supports Citrix, Terminal Server, Windows 8, Windows Server 2012, Windows 7, Vista, 2008R2, 2008, 2003, and 2000. Works with 32 and 64 bit systems.
ScanTailor - Scan Tailor is an interactive post-processing tool for scanned pages.
PrimoPDF - Downloaded by 15+ million users. Get Nitro's PDF converter and quickly convert to PDF from 300+ file types. PrimoPDF — the 100% FREE PDF creator! PrimoPDFDownloaded by 15+ million users.
Briss - Cross-platform application for cropping PDF files in a simple and fast way via a GUI.
Ghostscript - Documentation.