IBM Lotus Symphony is a free office suit that has a word processor, spreadsheet and a presentation program. It supports the OpenDocument format (ODF), as well as the binary Microsoft Office and Lotus Smartsuire formats. One of the really good features is the fact that it can export documents in PDF format.
Symphony is based on OpenOffice techoloy and uses the Eclipse Rich Client for it's framework.
It is available fon Windows, Linux and Mac, and best of all it's free!