LibreOffice - Writer - Open-source cross-platform word processor.
PDF Joiner - This online tool allows you to join several PDF documents into a single file, free of charge.
Microsoft Word - Microsoft Word is a commercial word document processor for Windows.
PDFChef Merge PDF - PDFChef Merge PDF is an online tool that allows you to merge multiple PDf files into one quickly and securely.
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.
PDFill - Open, View, Edit, Save and Print PDF Documents without Adobe Acrobat