The function library package with the modules (dll) PDFinternals, PDFdocuments, PDFlayout and PDFsecurity for your own (batch-)application.
Here bundled for a lower price! You can use the dlls with your commercial applications without paying any further royalty fees! The dlls are tested with delphi and vba/visual basic... but there should be no problems with any other main programming language, too. Please read more on the product pages.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.