Open Office is the open source alternative to Microsoft Office, and does a great job of competing with it's commercial rival. You can open most, if not all Microsoft documents in Open Office with minimal formatting errors, and even save documents in Microsoft formats that open up pretty well in Office. Open Office also comes with a word processor like Microsoft Word, a spreadsheet component like Microsoft Excel, and a presentation component like Microsoft Powerpoint. Open Office even comes with a drawing component that has some nice options to create your own digital art. The only thing Open Office seems to lack right now is database capability like Microsoft Access, but not everyone needs that anyway.