Convert CSV to Excel file in C#.NET from ASP.NET web pages or windows application by EasyXLS library! XLS, XLSX, XLSM, XLSB in .NET.
https://www.easyxls.com/manual/tutorials/csharp/convert-csv-to-excel.html

Export data to CSV file in PHP using EasyXLS library! Spreadsheets in PHP.

https://www.easyxls.com/manual/tutorials/php/export-data-to-csv-file.html

Convert Excel file to CSV in C#, VB.NET, Java, PHP, ASP classic, C++, C++.NET, VB6, VBS! XLS, XLSX, XLSM, XLSB spreadsheets by EasyXLS.

https://www.easyxls.com/manual/basics/convert-excel-to-csv.html

Convert CSV file to Excel in C#, VB.NET, Java, PHP, ASP classic, C++, C++.NET, VB6! XLS, XLSX, XLSM, XLSB spreadsheets by EasyXLS.

https://www.easyxls.com/manual/basics/convert-csv-to-excel.html

Import data from CSV in C#, VB.NET, Java, PHP, ASP classic, C++, C++.NET, VB6 and more! XLS, XLSX, XLSM, XLSB spreadsheets by EasyXLS. https://www.easyxls.com/manual/basics/import-from-csv-file-format.html