PDF Split and Merge tool is implemented using the PdfSharp library and is either GUI or command driven.It is useful for automated document creation.It allows bookmarks from the input pdfs to be imported and flexibly embedded in the destination document. PDF pages can be numbered and annotated with a footer label.
Xom (Xml Object Model) is a lightweight, powerful, and extensible framework for representing Java gui elements. Also, general java gui tools/frameworks for creating impressive user interfaces. Includes a basic PDF viewer, and various gui components.