As others have said, Open Office is becoming the de facto free MS Office download. However, there is a 'new' kid on the block in Lotus Symphony - they even give help in switching from MS Office. (You could also check out Google's on-line packages).
http://symphony.lotus.com/software/lotus/symph ony/home.jspa
Switching to Lotus Symphony is easy.
Check out our reference cards to learn how easy it is to switch from Microsoft� Word�, Microsoft� PowerPoint�, or Microsoft� Excel�.