Open Office, included in the list provided by Midway, works just fine and the files are compatible with MS Office,
http://www.openoffice.org/.
To create basic documents you can use Docs and Spreadsheet by Google. You can share documents or even upload and edit your Word Documents. The files are kept online, you get 2.8GB of free space and documents can be access from any PC connected to the Internet.
Just go to
www.google.com and type Docs and Spreadsheet.