Libxlsxwriter is a C library that can be used to write text, numbers, formulas and hyperlinks to multiple worksheets in an Excel 2007+ XLSX file. It supports features such as:

Excelize is described as 'Library written in pure Go providing a set of functions that allow you to write to and read from XLAM / XLSM / XLSX / XLTM / XLTX files. Supports reading and writing spreadsheet documents generated by Microsoft Excel 2007 and later' and is a Spreadsheet app in the office & productivity category. There are four alternatives to Excelize for Mac, Windows, Linux, BSD and iPhone. The best Excelize alternative is libxlsxwriter, which is both free and Open Source. Other great apps like Excelize are LibXL, libxls and readxl.
Libxlsxwriter is a C library that can be used to write text, numbers, formulas and hyperlinks to multiple worksheets in an Excel 2007+ XLSX file. It supports features such as:

LibXL is a library that can read and write Excel files. It doesn't require Microsoft Excel and .NET framework, combines an easy to use and powerful features.
libxls, a C library for reading Excel files in the nasty old binary OLE format, plus a command-line tool for converting XLS to CSV (named, appropriately enough, xls2csv).
The readxl package makes it easy to get data out of Excel and into R. Compared to many of the existing packages (e.g. gdata, xlsx, xlsReadWrite) readxl has no external dependencies, so it’s easy to install and use on all operating systems.