Class Libraries & REST APIs for the developers to manipulate & process Files from Word, Excel, PowerPoint, Visio, PDF, CAD & several other categories in Web, Desktop or Mobile apps. Develop & deploy on Windows, Linux, MacOS & Android platforms....EXCEL_97_TO_2003 ); // Save in Excel2007 (XLSX) format $workbook -> save (...$dataDir . "book.out.xlsx" , $fileFormatType -> XLSX ); // Save in SpreadsheetML...