Go to http://porting.openoffice.org/mac/download/x11.html
Click on the link labelled "Mac OS X 10.4.x (Tiger) or Mac OS X 10.5.x (Leopard)" to go to http://porting.openoffice.org/mac/download/x11-104.html
Click on Intel to get to the 2.3.1 download at http://porting.openoffice.org/mac/download/x11-104-Intel.html
Click on PowerPC Mac to get to the relevant downloads at http://porting.openoffice.org/mac/download/x11-104-PPC.html - but 2.3.1 is currently only available for the German version.
OpenOffice.org
full-featured office productivity suite
Version: 3.0