Open Office is the open source version of Star Office 6.0, which is a product of Sun Microsystems. It is available without cost from http://www.openoffice.org/ - the latest version is 1.1, which is almost totally compatible with Microsoft Office 2000 file formats. (Version 1.0 had a few page layout issues)

• Both Open Office and Star Office are XML compatible office productivity suites, as are Microsoft Office 2000 and Office XP (to a more or less limited extent - Microsoft's Office 11, currently in development, will be fully XML compatible)
• Because Open Office is licensed under the provisions if the LGPL/SISSL agreements, everyone is able to use it free of charge. By contrast, every copy of Microsoft Office that is installed in a business requires a separate EULA/COA license and is subject to audit verification with potentially heavy financial penalties for installation of unlicensed products.