Open source PDF editor
Cross-platform SDK for creating and modifying PDF documents
PDF transformation/manipulation program + library
Prepress preparing tool and PDF editor
converts PostScript or PDF files to other vector graphics formats
Gerber to PDF converter
a graphical user interface for the PDF Toolkit (PDFtk)
A PDF parsing, modification and creation library.
Convert HTML to PDF using Webkit (QtWebKit)
Manage your collection of PDF files