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....= 30 ; //Add formula in cell A4 cellA4 . Formula = "=Sum(A1:A3)"...= 30 ; //Add formula in cell A4 cellA4 . Formula = "=Sum(A1:A3)"...