CleverPDF is a comprehensive PDF web app, which offers 27 PDF tools online for free. It helps users convert PDF to Office, iWork, images and more. Users can also compress PDF, merge or split PDF, rotate PDF, add watermark or numbers to PDF and more. It's completely free, no sign-up is required.
PDF Joiner - This online tool allows you to join several PDF documents into a single file, free of charge.
Wondershare PDFelement - All-in-one PDF editor
DocuPUB - DocuPUB is an online file converter, file merger, file compressor, and file resizing tool.
Foxit PhantomPDF - Edit PDF files with our feature-rich PDF Editor. Download Foxit PDF Editor to convert, sign, scan / OCR & more. A speedy PDF Editor alternative to Adobe Acrobat.
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.