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....//Save in default (Excel2003) format $workbook -> save ( $dataDir...xls" ); //Save in Excel2003 format $workbook -> save ( $dataDir...