File formats, methods, and computer program products are provided for representing a workbook in a modular content framework. The modular content framework may include a file format container associated with modular parts. A file format includes logically separate modular parts that are associated with...http://www.google.co.uk/patents/US7617444?utm_source=gb-gplus-sharePatent US7617444 - File formats, methods, and computer program products for representing workbooks
