Open Source - Office Suites
http://www.openoffice.org/
OpenOffice.org is a multiplatform and multilingual office suite and an open-source project. Compatible with all other major office suites, the product is free to download, use, and distribute.
http://www.staroffice.com/
StarOffice Open Source Office Suite.
http://www.gnome.org/gnome-office/
GNOME Office empowers you with three "best in class" productivity applications available as GNU Free Software. The times of wrestling with file formats, compatibility, and 'halfway-there' features is over. The AbiWord word processor, Gnumeric spreadsheet, and Gnome-DB data access components allow you to get it done now.