OpenOffice.org is a FreeSoftware office suite available for many platforms. Writer, the word processor of OpenOffice, is nothing like Emacs. Though people have petitioned that Emacs key bindings be imported.
For information on using Emacs to develop OpenOffice, see the Editor Emacs entry on the OpenOffice.org Wiki
OpenOffice stores data in OpenDocument format, which you can partially view and edit in Emacs too.