Manipulating a pre-existing PDF file
Developer: PDF labs
PDFtk Free (PDFtk Server in command line and GUI version) is a graphical tool for quickly merging and splitting PDF documents and pages. It will convert text and HTML to PDF and allows the addition of background images.
It is also useful as an alternative file viewer and PDF printer solution in KDE for Evince which has the GNOME interface. The preferences dialogue which has to be set up as to binary location for both the command line program (/usr/bin/pdftk) and a PDF viewer makes this easily possible.