What are some alternatives?
When comparing PDFTK Builder and Adobe Acrobat DC, you can also consider the following products
PDFsam - PDFsam Basic, a free, open source, multi-platform software designed to split, merge, extract pages, mix and rotate PDF files
PDFelement - All-in-one PDF editor
PDF-Shuffler - PDF-Shuffler is a small python-gtk application, which helps the user to merge or split pdf...
Google Drive - Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
PDFill - Open, View, Edit, Save and Print PDF Documents without Adobe Acrobat
Foxit PhantomPDF - Edit PDF files with our feature-rich PDF Editor. Download Foxit PDF Editor to convert, sign, scan / OCR & more. A speedy PDF Editor alternative to Adobe Acrobat.