XLware LibXL (enterprise license - 1 year support & updates)
LibXL: C++ Excel Library to read/write xls/xlsx files: LibXL is a library for direct reading and writing of Excel files (xls/xlsx) without OLE automation and Microsoft Excel. Supports C, C++, C#.NET, Delphi and other languages. 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. Library can be used to Generate a new spreadsheet from scratch, Extract data from an existing spreadsheet, Edit an existing spreadsheet. LibXL can help your applications in exporting and extracting data to/from Excel files with minimum effort. Also it can be used as report engine.