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 command-line 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
• Decrypt Input as Necessary (Password Required)
• Encrypt Output as Desired
• Fill PDF Forms with FDF Data and/or Flatten Forms
• Apply a Background Watermark
• 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)