P4Software 

Lightweight, dependency-free, MIT-licensed .xlsx library for .NET: streaming writer with tables, charts, pictures, conditional formatting, validation, protection and AutoFit, plus a streaming reader. A free... More information

ASP.NET Core helpers for SheetStream: return a streamed .xlsx download from a minimal API or controller in one line, with flat memory and no synchronous I/O.

Lightweight, dependency-free, MIT-licensed .xlsx library for .NET: streaming writer with tables, charts, pictures, conditional formatting, validation, protection and AutoFit, plus a streaming reader. A free... More information