.NET

Vanaradahall/Vanara

A comprehensive set of .NET libraries providing P/Invoke calls and wrappers for native Windows APIs.

MimeKitjstedfast/MimeKit

A high-performance .NET library for creating and parsing MIME messages with support for S/MIME, PGP, DKIM, TNEF, and Unix mbox.

PropertyChanged.FodyFody/PropertyChanged

A Fody add-in that automatically injects INotifyPropertyChanged event-raising code into property setters at compile time.

Identityaspnet/Identity

ASP.NET Core Identity is the membership system for building ASP.NET Core web applications with authentication and user management.

NBitcoinMetacoSA/NBitcoin

A comprehensive Bitcoin library for .NET, implementing all major Bitcoin Improvement Proposals (BIPs) and providing low-level primitives.

dotnet-formatdotnet/format

A command-line tool for automatically formatting .NET code to follow style guidelines and conventions.

.NEXT Raftdotnet/dotNext

A high-performance .NET library suite for low-allocation scenarios like microservices, distributed systems, and database engines.

ATFSonyWWS/ATF

A C#/.NET framework for building custom Windows-based authoring tools, used extensively in Sony game development.

ITextitext/itext-dotnet

A high-performance .NET library for creating, manipulating, inspecting, and maintaining PDF documents.

Rogue Legacyflibitijibibo/RogueLegacy1

Source code for the original Rogue Legacy game, built with the FNA framework.

DocXxceedsoftware/DocX

A .NET library for creating and modifying Microsoft Word (.docx) files without requiring Microsoft Office.

Stl.Fusionservicetitan/Stl.Fusion

A .NET library for building real-time apps with transparent caching and automatic dependency tracking, requiring minimal extra code for live updates.

Proto.actorAsynkronIT/protoactor-dotnet

Ultra-fast, distributed, cross-platform actor framework for Go, C#, and Java/Kotlin.

RepoDbmikependon/RepoDb

A high-performance hybrid ORM library for .NET that bridges micro-ORMs and full-ORMs with advanced features.

DynamicDataRolandPheasant/DynamicData

A .NET library that brings Reactive Extensions (Rx) to collections, enabling reactive and declarative in-memory data management.

Dynamic Datareactivemarbles/DynamicData

A .NET library that brings Reactive Extensions (Rx) to collections, enabling reactive and declarative in-memory data management.

geometry3Sharpgradientspace/geometry3Sharp

A C# library for 2D/3D geometric computing, mesh algorithms, and spatial data structures, compatible with Unity.

SIPSorcerysipsorcery/sipsorcery

A comprehensive real-time communications library for .NET that enables VoIP and WebRTC capabilities in applications.

AdonisUIbenruehl/adonis-ui

A lightweight UI toolkit for WPF applications offering classic but enhanced Windows visuals with runtime theme switching.

LINQKitscottksmith95/LINQKit

A set of extensions for LINQ to SQL and Entity Framework that enables expression composition, dynamic predicates, and subquery expression variables.

Npgsql.EntityFrameworkCore.PostgreSQLnpgsql/Npgsql.EntityFrameworkCore.PostgreSQL

Entity Framework Core provider for PostgreSQL, enabling .NET developers to interact with PostgreSQL databases using LINQ.

DotNetCorePluginsnatemcmaster/DotNetCorePlugins

A .NET library for dynamically loading assemblies as plugins with dependency isolation and type sharing.

LibVLCSharpvideolan/libvlcsharp

Cross-platform .NET/Mono bindings for LibVLC, providing a comprehensive multimedia API for audio and video playback, streaming, and encoding.

Fluidsebastienros/fluid

A fast, secure .NET template engine implementing the Liquid language with async support and extensibility.

Monogame.ExtendedMonoGame-Extended/Monogame-Extended

A collection of libraries and tools that extend MonoGame to simplify 2D game development.

EntityFramework.ExceptionsGiorgi/EntityFramework.Exceptions

A library that provides strongly typed exceptions for handling database errors in Entity Framework Core and ADO.NET.

System.Linq.Dynamic.CoreStefH/System.Linq.Dynamic.Core

A .NET library for writing dynamic LINQ queries using string expressions, supporting .NET Core, .NET Standard, and .NET Framework.

Unityunitycontainer/unity

A full-featured, extensible dependency injection container for building loosely coupled .NET applications.

HtmlSanitizermganss/HtmlSanitizer

A .NET library for cleaning HTML fragments and documents to prevent XSS attacks using a robust HTML parser.

NetTopologySuiteNetTopologySuite/NetTopologySuite

A .NET port of JTS Topology Suite providing fast and reliable 2D geometric operations for GIS applications.

Roslyn Analyzersdotnet/roslyn-analyzers

Roslyn-based analyzers for .NET code quality, security, and maintainability, replacing legacy FxCop.

Fluent NHibernatenhibernate/fluent-nhibernate

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

Downloaderbezzad/Downloader

A fast, cross-platform, and reliable multipart downloader library for .NET applications with asynchronous progress events.

Oouipraeclarum/Ooui

A cross-platform .NET UI library that brings native UI development simplicity to the web using web technologies.

Finbuckle.MultiTenantFinbuckle/Finbuckle.MultiTenant

An open-source multi-tenancy library for modern .NET enabling tenant resolution, per-tenant app behavior, and data isolation.

EmbedIOunosquare/embedio

A tiny, cross-platform, module-based web server for .NET, enabling lightweight web applications and REST APIs.