Free and open source GUI application for manipulating PDF files using the Windows version of PDF Toolkit (PDFtk) - split, merge, stamp, number pages, rotate, metadata, bookmarks, attachments, etc. This project is a fork of PDFTK Builder by Angus Johnson that enhances the user interface, adds functions, and enables use of later versions of PDFtk. OS: Windows. Author: David King. License: GPLv3.