Older versions of Office, like Office 2000, Office 2003 and Office XP will get supports for these new XML file formats. Microsoft says it will release updates allowing them to read, edit and save files using the new file formats. A conversion tool to convert files from the old Office format to the new Office 12 XML format will also be released.
Microsoft is committing to publish the forthcoming XML formats and make them available under the same royalty-free license under which the current Office 2003 file formats are. Licensees will be able to integrate these formats into their servers, applications and business processes "without financial consideration to Microsoft," according to the Redmond software vendor.XML uses more space than the current formats so Microsoft decided to utilize zip compression. They said it will result in up to 75 percent smaller files than with the current Office format. Office 12 is planned for the second half of next year. More details at Microsoft Watch