FastMember by: Marc Gravell

In .NET reflection is slow... well, kinda slow. If you need access to the members of an arbitrary type, with the type and member-names known only at runtime - then it is frankly hard (especially for DLR types). This library makes such access easy and fast.

Fhir.Metrics by: Martijn Harthoorn

Conversion system for physical units, with UCUM implementation - The Unified Code for Units of Measure

FastEndpoints by: FastEndpoints

A light-weight REST Api framework for ASP.Net 6 and newer that implements REPR (Request-Endpoint-Response) Pattern.

CryptoHelper.StrongName by: Henk Mollema

Standalone password hasher for ASP.NET Core using a PBKDF2 implementation.

ExcelNumberFormat by: ExcelNumberFormat developers

.NET library to parse ECMA-376 number format strings and format values like Excel and other spreadsheet softwares.

FastExpressionCompiler by: Maksim Volkau

FastExpressionCompiler is 10-40x times faster than Expression.Compile()

DotNetAnalyzers.PublicApiAnalyzer by: Sam Harwell et. al.

An analyzer for packages with public APIs.

Elmah.Io.AspNetCore by: elmah.io

An elmah.io provider for ASP.NET Core

CSharpFunctionalExtensions by: Vladimir Khorikov

CSharpFunctionalExtensions - functional extensions for C#.

CsvHelper by: Josh Close

A library for reading and writing CSV files. Extremely fast, flexible, and easy to use. Supports reading and writing of custom class objects.

FastMember.Signed by: Marc Gravell

In .NET reflection is slow... well, kinda slow. If you need access to the members of an arbitrary type, with the type and member-names known only at runtime - then it is frankly hard (especially for DLR types). This library makes such access easy and fast.

DocumentFormat.OpenXml by: Microsoft

The Open XML SDK provides tools for working with Office Word, Excel, and PowerPoint documents. It supports scenarios such as: - High-performance generation of word-processing documents, spreadsheets, and presentations. - Populating content in Word files from an XML data source. - Splitting up (shredding) a Word or PowerPoint file into multiple files, and combining multiple Word/PowerPoint files into a single file. - Extraction of data from Excel documents. - Searching and replacing content in Word/PowerPoint using regular expressions. - Updating cached data and embedded spreadsheets for charts in Word/PowerPoint. - Document modification, such as removing tracked revisions or removing unacceptable content from documents.

Dapper by: Sam Saffron Marc Gravell Nick Craver

A high performance Micro-ORM supporting SQL Server, MySQL, Sqlite, SqlCE, Firebird etc..

EPPlus by: Jan Källman

A library to manage Excel spreadsheets, using OOXML.

DeviceId by: Matthew King

Provides functionality to generate a 'device ID' that can be used to uniquely identify a computer.

FluentAssertions by: Dennis Doomen Jonas Nyrup Xceed

A very extensive set of extension methods that allow you to more naturally specify the expected outcome of a TDD or BDD-style unit tests. Works with .NET Standard 2.0 and higher, .NET Framework 4.7 and higher and .NET 6 and higher. Supports the unit test frameworks MSTest2, NUnit3, NUnit4, XUnit2, XUnit3, MSpec and TUnit. IMPORTANT: This version is free for open-source projects and non-commercial use, but commercial use requires [a paid license](https://xceed.com/products/unit-testing/fluent-assertions/). Check out the [license page](LICENSE) for more information.

FastEndpoints.Swagger by: FastEndpoints

Swagger support for FastEndpoints.

Elmah.Io.Client by: elmah.io

.NET client for communicating with the elmah.io REST API

DotNetAnalyzers.PublicApiAnalyzer.Unstable by: Sam Harwell et. al.

An analyzer for packages with public APIs.

DotLiquid by: Tim Jones Alessandro Petrelli

DotLiquid is a templating system ported to the .NET framework from Ruby’s Liquid Markup.