Examine by: Shannon Deminick

Examine is a wrapper for getting a Lucene index up and running for any type of data and comes with an API to search it. You can either use the Fluent API that the library comes with or use raw Lucene query syntax. The indexing is configurable and will allow both synchronous and asynchronous indexing and everything works happily in web projects too.

GeoAPI.CoordinateSystems by: NetTopologySuite Team

GeoAPI.NET project provides a common framework based on OGC/ISO standards to improve interoperability among .NET GIS projects.

FluentValidation by: Jeremy Skinner

A validation library for .NET that uses a fluent interface to construct strongly-typed validation rules.

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.

EntityFramework by: Microsoft

Entity Framework 6 (EF6) is a tried and tested object-relational mapper for .NET with many years of feature development and stabilization.

Fody by: The Fody Team

Extensible tool for weaving .net assemblies.

GemBox.Spreadsheet by: GemBox

GemBox.Spreadsheet is a .NET component that enables you to read, write, convert, and print spreadsheet files (XLSX, XLS, XLSB, CSV, HTML, and ODS) from .NET applications. With GemBox.Spreadsheet you get a fast and reliable component that's easy to use and doesn't depend on Microsoft Excel. It requires only .NET and it's much faster than Microsoft Office Automation!

Elasticsearch.Net by: Elastic and contributors

Elasticsearch.Net

GeoAPI by: NetTopologySuite Team

GeoAPI.NET project provides a common framework based on OGC/ISO standards to improve interoperability among .NET GIS projects.

ExcelNumberFormat by: ExcelNumberFormat developers

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

Esprima by: Sebastien Ros

Standard-compliant ECMAScript 2016 parser (also popularly known as JavaScript or ES6).

DotNetAnalyzers.PublicApiAnalyzer by: Sam Harwell et. al.

An analyzer for packages with public APIs.

DotNetZip by: Dino Chiesa

DotNetZip is an easy-to-use, FAST, FREE class library and toolset for manipulating zip files or folders.

GeoAPI.Core by: NetTopologySuite Team and Fabrício Godoy

GeoAPI.NET project provides a common framework based on OGC/ISO standards to improve interoperability among .NET GIS projects.

Gee.External.Capstone by: Ahmed Garhy (@9ee1)

Capstone.NET is an opinionated .NET Core and a .NET Framework binding for the Capstone disassembly framework. It is written in C#, supports Capstone 4, and has a friendly and simple type safe API that is ridiculously easy to learn and quick to pick up.

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.

FluentNHibernate by: James Gregory and contributors

Fluent, XML-less, compile safe, automated, convention-based mappings for NHibernate.

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.

dotless.AspNetHandler by: Daniel Hölbling, James Foster, Luke Page

Adds HTTPHandler for ASP.NET to compile LESS files on demand. This is a project to port the hugely useful Less libary to the .NET world. It give variables, nested rules and operators to CSS. For more information about the original Less project see http://lesscss.org/ or http://github.com/dotless/dotless. For more information about how to get started with the .NET version see http://www.dotlesscss.org/.

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

An analyzer for packages with public APIs.