Open Office

Open Office is an office sweet the closely rivals Microsoft office. It can handle Microsoft office files and files can be output as Microsoft office files. It has most features that Microsoft office has, and more. It has Writer that resembles Word, Calc that resembles Excel, Impress that resembles PowerPoint, and many more applications. It uses Java so it is available for Windows, Mac OS X, and Linux. Check it out at openoffice.org

Writer