If PDF is electronic paper, then pdftk is an electronic staple-remover, hole-punch, binder, secret-decoder-ring, and X-Ray-glasses. Pdftk is a simple tool for doing everyday things with PDF documents. Keep one in the top drawer of your desktop and use it to:
Merge PDF Documents
Split PDF Pages into a New Document
Rotate PDF Pages or Documents
Decrypt Input as Necessary (Password Required)
Encrypt Output as Desired
Fill PDF Forms with FDF Data or XFDF Data and/or Flatten Forms
Apply a Background Watermark or a Foreground Stamp
Report on PDF Metrics such as Metadata, Bookmarks, and Page Labels
Update PDF Metadata
Attach Files to PDF Pages or the PDF Document
Unpack PDF Attachments
Burst a PDF Document into Single Pages
Uncompress and Re-Compress Page Streams
Repair Corrupted PDF (Where Possible)
Pdftk allows you to manipulate PDF easily and freely. It does not require Acrobat, and it runs on Windows, Linux, Mac OS X, FreeBSD and Solaris.
This is a command line utility. See pdfchain.html for its graphical user interface