GabrielMatte 

High-performance, low-allocation .NET library for reading and writing XLSX, XLSB, XLS, and CSV — streaming readers, typed row parsing, and workbook writers for all four formats.

Apache Arrow RecordBatch conversion for ExcelReader.NET.

Command-line workbook inspection and CSV conversion, built on ExcelReader.NET.

High-performance, low-allocation parsing and writing of fixed-width (flat) files for .NET. Attribute-driven column mapping, sync/async batch reading (IEnumerable/IAsyncEnumerable), configurable formatting,... More information