Extension:PHPExcel

The PHPExcel extension is a container for the PHPExcel library. Installing this extension will make PHPExcel's functionality available for other extensions to use.

If you are using composer as depenency management, you don't need to install this extension. The extension is just a wrapper to load the PHPExcel library correctly. Using composer you can easily get the official distribution of the library.

Installing through composer
composer require phpoffice/phpexcel