Google 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.

PDFtk - PDFtk is a simple tool for doing everyday things with PDF documents.

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.

AutoMetadata - AutoMetadata is a tool for exploring and manipulating metadata, document properties, and viewer preferences in multiple PDF documents.

Wondershare PDFelement - All-in-one PDF editor

Pdfinfo - Pdfinfo is a PDF document information and metadata extractor tool.