With Sun Microsystems 'Open Office' you can save files in virtually any format you would like. That way you can assure that any recipient will be able to view the file in the way you intended. While I own and use Office 2003, 2007 and Open Office, I must admit I am getting tired of the constant upgrade cost associated with Microsoft products. I use Excel professionally for my day to day proposals. Open Office seems to handle all the formulas very well and allows me to create and edit and save as .XLS or any other spreadsheet type. It truly is remarkable to have an office suite that works very well and is truly free. While I use spreadsheet software predominantly, Open Office has most every other program application that Microsoft Office has. If you can use MS Office, you can certainly use and understand Open Office. www.openoffice.org