OpenOffice.org is the open-source, quintessential productivity suite and free alternative to famous programs like Apple iWork and Microsoft Office.
OpenOffice.org includes a word processor (Writer), a formula page (Formula), a data base utility (Database), a tool for creating slideshows (Presentation) and another for schematic representations (Drawing).
OpenOffice.org finally has a native version for Mac, which is why it doesn't need to run the X11 server (only available for Mac OS X Intel for now).
Although OpenOffice.org doesn't automatically run the guide that allows you to select the kind of document you want, you can access the different applications from the corresponding menu bar: Text Document, Spreadsheet, Presentation, Database, or Drawing.
In addition, it is compatible with the main Microsoft Office file formats, which is why you can use OpenOffice to open PPS or PPT from PowerPoint on Mac or Word documents in DOC format.