Open Office download (See links below) is a disc image file (.dmg). Double click on the .dmg icon and you are presented with an icon labelled openoffice.org and another icon which is an alias to your Applications folder. Simply drag the openoffice icon onto the Applications folder icon and Open Office will be copied into the Applications folder. Double click on the Open Office icon in your Applications folder to launch Open Office. There is a version of Open Office called Neo Office that is tweaked specifically for Mac OS X.