What are some alternatives?
When comparing PDFTK Builder and PDFsam, you can also consider the following products
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
PDF-Shuffler - PDF-Shuffler is a small python-gtk application, which helps the user to merge or split pdf...
PDFill - Open, View, Edit, Save and Print PDF Documents without Adobe Acrobat
iSafePDF - iSafePDF is a free open source PDF protection software.
PDF-XChange Editor - The smallest, fastest, most feature-rich PDF editor/viewer available
PDFelement - All-in-one PDF editor