.NET

OneOf provides discriminated unions for C# with exhaustive compile time matching.

Algorithm and data-structure library for .NET 3.5 and up. Algorithmia contains sophisticated algorithms and data-structures like graphs, priority queues, command, undo-redo and more.

data structures, algorithms, mathematics, metadata, extensions, console, measurements, and other useful stuff

A convenient data structure supporting efficient in-memory indexing and querying, including range queries and fuzzy string matching.

High-performance middleground between classic ASP.NET Core API controllers and Minimal APIs. Using a REPR (Request-Endpoint-Response) pattern, this library eliminates the boilerplate and monolithic feel of controllers by improving colocation of code.

.NET Client for Telegram Bot API

Automate a user account on Telegram, using the latest version of Telegram Client API

Mobius adds C# language binding to Apache Spark, enabling the implementation of Spark driver code and data processing operations in C#.

.NET core API Gateway

Command Query Separation for ASP.NET Core AWS Lambda Azure Functions Google Cloud Functions ASP.NET Web API 2

A .NET library allows clients to specify the exact fields they need, reducing unnecessary data transfer by avoiding the retrieval of all fields by default.

A set of libraries and classes that simplify building REST APIs and gRPC services, reducing the amount of code to be written with even one line of code for a fully functional REST controller.

JSON, JSV and CSV Text Serializers used in servicestack.net

Very simple & lightweight CSV exporter, Excel friendly, escapes text & quotes etc.

Protocol buffers is the name of the binary serialization format used by Google for much of their data communications

Popular high-performance JSON framework for .NET

MessagePack implementation for Common Language Infrastructure

Fast, idiomatic FlatBuffers implementation. Use .fbs files or attributes.

A high performance polymorphic serializer for the .NET framework.

Fast and flexible serialization framework usable on undecorated classes.

Serializes in-memory object to C# code.

A profile-based Serializer for multiple data-formats.

.NET Core Extensions and Helper NuGet packages

A starting point for new modern ASP.NET MVC web applications with best practices and most popular tools.

The next generation of the ASP.NET Boilerplate web application framework.

business layer development framework https://cslanet.com/

Open source ECMA CLI, C#, F#, VB and .NET implementation

Peasy is a middle tier framework that offers an easy to use and flexible rules engine and was designed to address common challenges such as concurrency handling, transactional support, fault tolerance, threading, scalability, async and multiple client support, and easy testability, all without a huge learning curve!

Plastic provides encapsulation of things like Domain, Application Rules, Business Rules or Business Logic in Application. For this, Command pattern is used.

Signals is a .NET5 based framework which focuses on increasing the quality and productivity within development teams by providing them with tools, aspects and processes.

DotNetty is a port of Netty, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients.

AspectCore Framework is an Aspect-Oriented Programming based cross platform framework for .NET Core and .NET Framework. Core support for aspect-interceptor,dependency injection integration , web applications , data validation , and more.

.NET Core and Blazor library that attempts to dramatically improve the way we implement real-time and high-load services by introducing a novel kind of "computed observables" - immutable, thread-safe, and most importantly, almost invisible for developers. Samples 1 Samples 2

The Silky framework is designed to help developers quickly build a microservice development framework through simple code and configuration under the .net platform.

An advanced Web View (PositronWebView) with native JavaScript Context to access .NET APIs from hybrid applications inspired from capacitor/cordova.

Skip SignalR and gRPC. Build real-time Blazor and MAUI apps while writing just 0.1% of the usual real-time update code. Handle 10× more API requests with the ActualLab.Rpc protocol—or 1000× more with Fusion’s transparent and perfectly coherent caching. Samples. Documentation.

Orleans is a framework that provides a straight-forward approach to building distributed high-scale computing applications, without the need to learn and apply complex concurrency or other scaling patterns. It was created by Microsoft Research.

Raft implementation for .NET and ASP.NET Core that allows to build clustered microservices powered by distributed consensus and replication

Orleankka is a functional API for Microsoft Orleans framework. It is highly suitable for scenarios where having composable, uniform communication interface is preferable, such as: CQRS, event-sourcing, re-routing, FSM, etc. Additional API available for F# called Orleankka.FSharp.

Akka.NET is a port of the popular Java/Scala framework Akka to .NET. This is a community-driven port and is not affiliated with Typesafe who makes the original Java/Scala version.

Zebus is a lightweight, highly versatile, peer-to-peer service bus, built with CQRS principles in mind. It allows applications to communicate with each other in a fast and easy manner. Most of the complexity is hidden in the library and you can focus on writing code that matters to you, not debugging messaging code. A very fundamental base for any distributed application.

Proto Actor - Ultra fast distributed actors for Golang and C#

Spring.NET is an open source application framework that makes building enterprise .NET applications easier

An addictive .NET IoC container

Simple, fast all fully featured IoC container.

The ninja of .NET dependency injectors

A fast IoC container heavily optimized for usage within ASP.NET Core and other .NET server side applications.

An ultra lightweight IoC container

Simple Injector is an easy-to-use Dependency Injection (DI) library for .NET 4+ that supports Silverlight 4+, Windows Phone 8, Windows 8 including Universal apps and Mono.

Assembly scanning extensions for Microsoft.Extensions.DependencyInjection.

Managed Extensibility Framework (MEF) implementation used by Visual Studio.

A lightweight, portable dependency injection framework for .NET based solutions.

.NET project templates with batteries included, providing the minimum amount of code required to get you going faster.

backend: .NET Core, EF Core, C#; frontend: Babel, Webpack, React, CSS Modules

A prototypical .NET solution recommended by the F# Foundation---includes file system setup, Paket for dependencies and FAKE for build/test automation. By default, build process also compiles documentation and generates NuGet packages.

Serenity is an ASP.NET MVC application platform designed to simplify and shorten development of data-centric business applications with a service-based architecture. Serene is a starter template to build Serenity applications.

Large collection of useful templates for Web and Desktop development.

Windows 10 templates with design patterns.

Vue startup application template that uses ASP.NET Core API layered architecture at the back-end and JWT based authentication

JHipster blueprint for replace orginal SpringBoot Backend by asp.net core. The main goal generator of jhipster is showcases best practices of modern web development in java. So the goal of the project is to do the same in .net. The Frontend can be generated with angular or react and soon with blazor. - NOTE: This is not affiliated with Microsoft or .NET

C#/.NET Binding of llama.cpp, run LLaMA/GPT model using C# without having to compile lama.cpp.

One .NET library to consume OpenAI, Anthropic, Cohere, Google, Azure, Groq, and self-hosed APIs.

Extensible tool for weaving .NET assemblies.

Open-source alternative to ILMerge.

Cecil is a library to generate and inspect programs and libraries in the ECMA CIL form.

Modular extension for Microsoft ASP.NET Web Optimization Framework. Its modules supports LESS, Sass, CoffeeScript, TypeScript, Mustache, Handlebars, Autoprefixer along with a bunch of different JS and CSS minifiers.

A fully certified OpenID Connect server library for .NET by the OpenID Foundation, providing comprehensive support for OAuth2 and OpenID Connect across all profiles. [$][Free for non-commercial use]

New membership system for ASP.NET applications

SAML authentication support for ASP.NET apps

A F# Hawk authentication library

An IAM infrastructure for modern apps and SaaS products, supporting OIDC, OAuth 2.0 and SAML for authentication and authorization [$][Free for OSS]

Flexible and versatile OAuth 2.0/OpenID Connect stack for .NET

Add SAML 2P support to your OpenIddict [$]

Fast, in-memory background job processing for .NET apps with configurable queues, timeouts, parallelism, and built-in OpenTelemetry support.

A set of enterprise-class UI components based on Bootstrap and Blazor. - NOTE: This is not affiliated with Microsoft or .NET

A set of enterprise-class UI components based on Ant Design and Blazor WebAssembly.

A set of enterprise-class UI components based on Material Design and Blazor WebAssembly.

Blazorise is a component library built on top of Blazor and CSS frameworks like Bootstrap, Bulma and Material. Very easy to use.

k8s management ui in blazor and .NET Core.

A Material Design framework for Blazor, allowing .NET developers to quickly build web apps, with extensive documentation and examples.

full Ethereum client in .NET Core

.NET-based build automation tool written in PowerShell

F# Make, a cross-platform build automation system

PowerShell build and test automation tool inspired by Psake.

The Microsoft Build Engine (MSBuild) is the build platform for .NET and Visual Studio

Cake (C# Make) is a cross-platform build automation system with a C# DSL.

Magic script-based C# task runner

Cross-platform build automation system

A cross platform build and deployment automation system for building projects and executing deployment scripts using C# code. - NOTE: This is not affiliated with Microsoft or .NET

Write your pipelines in C#

The open source report generator for .NET Core 2.x/.Net Framework 4.x. FastReport can be used in ASP.NET MVC, Web API applications.

An ASP.NET Web API HTTP caching implementation both on client and server

An asynchronous, persistent key-value store

A caching library that contains basic and some advanced usages of caching which can help handle caching more easier! - NOTE: This is not affiliated with Microsoft or .NET

A common interface and abstraction layer for caching.

10X faster alternative to MemoryCache for .NET

An efficient multi-layered caching system for .NET (In-Memory, Redis, Database, File etc)

An easy to use, high performance and robust cache with an optional distributed 2nd layer and some advanced features, like a fail-safe mechanism and advanced timeouts management

Thread-safe in-memory caches optimized for very high concurrent throughput, near optimal hit rate and low latency.

A common interface with in-memory, Redis and Azure implementations.

An EventBus with local persistent message functionality for RabbitMQ or Kafka. - NOTE: This is not affiliated with Microsoft or .NET

Implementation of the Outbox pattern and OnceExecutor service that guarantees idempotence: the operation will be performed once

The most popular service bus for .NET

Incredibly easy way to perform fire-and-forget, delayed and recurring tasks inside ASP.NET applications

Implementation of an AMQP client library for C#, and a binding exposing AMQP services via WCF

NetMQ is 100% native C# port of ZeroMQ

MassTransit is lean service bus implementation for building loosely coupled applications using the .NET Framework.

Rebus is a lean service bus implementation for .NET, similar in nature to NServiceBus and MassTransit, only leaner

An easy to use .NET API for RabbitMQ

An easy to use service bus and microservices platform. Easily build applications and services in a visual IDE.

Confluent's .NET Client for Apache Kafka.

a .NET Stream Processing Library for Apache Kafka.

Command Dispatcher, Processor, and Distributed Task Queue https://www.goparamore.io/

Lightweight message bus with transports for popular messaging systems (Kafka, Redis, Azure Service Bus, and others) and in-memory communication.

Facilitates simple asynchronous messaging in dotnet apps.

iCal.NET is an iCalendar (RFC 5545) class library for .NET aimed at providing RFC 5545 compliance, while providing full compatibility with popular calendaring applications and libraries.

Official .NET API client for Stream Chat, a service for building chat applications.

Declarative CLI argument & XML configuration parser for F# applications.

Declarative framework for building command line interfaces.

Wrapper for command line interfaces.

Model your console app using C# in a composable manner. Define commands with methods. Define subcommands with properties or nested classes. Extensible parsing and command execution.

The Command Line Parser Library offers to CLR applications a clean and concise API for manipulating command-line arguments and related tasks

This is a fork of Microsoft.Extensions.CommandLineUtils, which is no longer under active development.

Command-line interface description language that will make you smile.

Terminal UI toolkit for .NET.

PowerArgs converts command-line arguments into .NET objects that are easy to program against. It also provides a ton of optional capabilities such as argument validation, auto generated usage, tab completion, and plenty of extensibility

A simple netsh library for C#.

A library that makes it easier to create beautiful console applications.

This is a fork of Microsoft.Extensions.CommandLineUtils, which is no longer under active development.

FluentCMS is open source AI Driven ASP.NET Core Blazor Content Management System (CMS)

A web CMS that focus on UX and adaptability

MojoPortal is an extensible, cross database, mobile friendly, web content management system (CMS) and web application framework written in C# ASP.NET

Free, open source, community-focused project aimed at delivering applications and reusable components on the ASP.NET platform

Piranha is the fun, fast and lightweight .NET framework for developing cms-based web applications with an extra bite. It's built on ASP.NET MVC and Web Pages and is fully compatible with both Visual Studio and WebMatrix. https://piranhacms.org

Umbraco is a free open source Content Management System built on the ASP.NET platform

Open source headless CMS and content management hub. https://squidex.io

RESTful CRUD (Create, Read, Update, Delete) APIs, Admin Panel web pages,a GraphQL-style query designer and a WYSIWYG web page designer, all fully configurable without writing code.

A number of Roslyn diagnostic analyzers initially developed to help flesh out the design and implementation of the static analysis APIs.

Powerful .NET library for benchmarking.

Static code analysis tool to enforce namespace dependency rules in C# projects.

Is a tool for benchmarking your Hypertext Transfer Protocol (HTTP) server.

A port of Clojure to the CLR in C#

Rewrite of Clojure CLR in F#

The F# programming language empowers everyone to write succinct, robust, and performant code

F# to JavaScript, TypeScript, JSX, Python, Dart, and Rust transpiler

Experimental Rust compiler for .NET.

Mono runtime embedded in Rust.

R6RS Scheme compiler, runtime and many standard libraries

A dynamically typed scripting language written in C# with a REPL, debugger, and simple embedding API

A Lua implementation on .NET in C#

Nemerle is a high-level statically-typed programming language for the .NET platform. It offers functional, object-oriented, and imperative features. It has a simple C#-like syntax and a powerful meta-programming system.

P is a language for asynchronous event-driven programming.

PeachPie is a PHP compiler and runtime for .NET and .NET Core, which allows entire PHP applications to run on the modern, secure and performant .NET and .NET Core platforms.

The .NET Compiler Platform ("Roslyn") provides open-source C# and Visual Basic compilers with rich code analysis APIs. It enables building code analysis tools with the same APIs that are used by Visual Studio.

Pascal implementation on .NET.

A Python 3 implementation that is integrated with the .NET framework.

A library for patching, replacing, and decorating .NET and Mono methods during runtime, mainly used for game modding.

A polyglot REPL built on .NET Interactive

SharpCompress is a compression library for .NET/Mono/Silverlight/WP7 that can unrar, un7zip, unzip, untar unbzip2 and ungzip with forward-only reading and file random access APIs. Write support for zip/tar/bzip2/gzip are implemented

A .NET Wrapper of Fast LZMA2 Algorithm. Write support for zip/tar/bzip2/gzip are implemented

AgileConfig is a lightweight configuration center that helps you manage all your application's configurations through website. - NOTE: This is not affiliated with Microsoft or .NET

A managed-only cryptography library for .NET which provides modern cryptographic primitives.

A Paseto (Platform-Agnostic Security Tokens) implementation for .NET

Managed .NET wrapper for unmanaged PKCS#11 libraries that provide access to the cryptographic hardware

.NET crypto library. Professionally audited.

.NET simple crypto library. Native c#.

A polycloud .NET cloud storage abstraction layer originally known as Storage.Net. Provides a generic interface for Blob storage (AWS S3, GCP, FTP, SFTP, Azure Blob/File/Event Hub/Data Lake) and Messaging (AWS SQS, Azure Queue/ServiceBus).

Bloat-free zero dependency .NET cloud storage kit that supports at minimum THE major cloud providers.

:- This library provides a universal interface for accessing and manipulating data in different cloud blob storage providers (Azure Storage, AWS S3, Google Cloud Storage. It makes it easy to switch between providers or to use multiple providers simultaneously, without having to learn and use multiple APIs.

C# binding for Facebook's RocksDB Key-Value store + native builds for Windows, macOS and Linux

DBreeze Database is an open-source embedded Key-Value store

The open-source, functional database with Complex Event Processing in JavaScript

A .NET NoSQL Document Store in a single data file - https://www.litedb.org

A LINQ-enabled document database for .NET

PostgreSQL as a document database and event store for .NET applications

A fast, easy-to-use alternative to SQLite & ORMs - https://realm.io/docs/dotnet/latest/

Event store for Azure Table Storage

Distributed in-memory platform: document database with SQL and LINQ support; distributed computations; distributed services and events.

A .NET document database working on any RDBMS

Simple JSON flat file data store with support for typed and dynamic data

Persistent, high-performance, transactional, and ACID-compliant ordered key-value database for .NET.

.NET data provider for DuckDB

.NET data provider for PostgreSQL

Official MongoDB C# driver

DataStax .NET driver for Apache Cassandra

Official Couchbase .NET client library, based on the Enyim memcached client

.NET client for rqlite (distributed relational DB based on SQLite)

Noda Time is an alternative date and time API for .NET. It helps you to think about your data more clearly, and express operations on that data more precisely. https://nodatime.org/

Common Date Time operations on the form of extensions to System.DateTime, including holidays and working days calculations on several culture locales.

DateTimeRange, Business Day and various DateTime, DateTimeOffset, TimeSpan extension methods.

open-source .NET assembly browser, editor, decompiler and debugger

Unofficial revival of dnSpy

.NET library helps you to deploy changes to SQL Server databases. It tracks which SQL scripts have been run already, and runs the change scripts that are needed to get your database up to date

Cross platform .NET standard libraries for DirectX, WIC, Direct2D1, XInput, XAudio and X3DAudio

Sucrose is a versatile wallpaper engine that brings life to your desktop with a wide range of interactive wallpapers.

Sandcastle Help File Builder similar to NDoc

Source browser website generator that powers https://referencesource.microsoft.com

Seamlessly adds a Swagger to Web API projects.

Tools for documenting F# and C# projects from F# script files, Markdown documents and inline XML or Markdown comments

Tools for building and publishing API documentation for .NET projects

Your friendly static documentation generator, using markdown files to build the content.

Swagger-like UI tool like Swagger, but for SignalR hubs — auto-discover your hubs, explore methods, invoke calls, and preview live client messages.

nopCommerce. Free open-source e-commerce shopping cart (ASP.NET Core)

Free ASP.NET Core MVC e-commerce Shopping Cart Solution

Stripe.net is a full service .NET API for https://stripe.com/

Virto Commerce is the second generation release and is the only enterprise level e-commerce product fully available under Open Source license. Virto Commerce is based on .NET 4.5 with extensive use of MVC, IoC, EF, Azure, AngularJS and many other cutting edge technologies. It can be deployed in Microsoft Cloud (Azure), Amazon Web Services (AWS) and on-premise. https://virtocommerce.com

Super simple ecommerce system built on .NET Core. Simple to use and easy to customize. Thanks to .NET Core, you can run the SimplCommerce on Windows, Linux. With various RDBMS: Microsoft SQL Server, PostgreSQL, MySQL

Headless, multi-vendor, multi-tenant, the most advanced open source e-commerce platform based on .NET Core 5.0 and MongoDB.

The official Adyen Payment API Library for .NET

BizHawk is a multi-system emulator written in C#. BizHawk provides nice features for casual gamers such as full screen, and joypad support in addition to full rerecording and debugging tools for all system cores.

The cross-platform .NET Core command-line toolchain utility.

ETL Framework for .NET (Read / Write CSV, Flat, Xml, JSON, Key-Value formatted files)

Lightweight ETL (extract, transform, load) library and data integration toolbox for .NET built on top of Microsoft TPL.Dataflow library.

A simple mediator for .NET for sending command, publishing event and request response with pipelines supported

Simple, unambitious mediator implementation in .NET

EventFlow is an Async/await first CQRS and Event Sourcing DDD framework for .NET

An easy-to-use and ambitious in-process mediator providing the foundation to implement Command Query Separation (CQS)

Exceptionless .NET Client

NLog - Advanced .NET and Silverlight logging

Open source NLog viewer for Windows

Elmah for MVC

Logary is a high performance, multi-target logging, metric, tracing and health-check library for Mono and .NET. .NET's answer to DropWizard. Supports many targets, built for micro-services.

Simplifies real-time remote error monitoring while using Rollbar.com. Open-source Rollbar Notifier SDK for any .NET-based technology stack. The SDK that can be used in any application built on the following .NET versions: .NET Core 2.0+, .NET Standard 2.0+, .NET Full Framework 4.5.1+, Mono, Xamarin, and, in general, any implementation of the .NET Standard 2.0+. It simplifies building data payloads based on exception data, tracing data, informational messages, and telemetry data and sends the payloads to the Rollbar API for remote monitoring and analysis of the hosting application's behavior. [Connects to Proprietary Service] [Free Tier]

.NET SDK for Sentry Open-source error tracking that helps developers monitor and fix crashes in real time..

A no-nonsense logging library for the NoSQL era. Combines the best of traditional and structured diagnostic logging in an easy-to-use package.

Error handler used for the Stack Exchange network

Cross-Platform (Windows/macOS/Linux) Universal Log Viewer which supports reading and parsing various type of logs. You can also define your own profile to parse and show logs.

ZeroLog is a zero-allocation .NET logging library. It provides basic logging capabilities to be used in latency-sensitive applications, where garbage collections are undesirable.

A source generator that automatically migrates all logging calls to high-performant LoggerMessage version.

This library provides a way to develop and expose application functionality based on feature flags. It enables scenarios like new feature rollouts and A/B testing for experimentation purposes. It also provides integration with common .NET coding patterns and ASP.NET Core.

This library uses and abuses the features of C# 6+ to provide a functional 'Base class library', that, if you squint, can look like extensions to the language itself. It also includes an 'Erlang like' process system (actors) that can optionally persist messages and state to Redis (note you can use it without Redis for in-app messaging). The process system additionally supports Rx streams of messages and state allowing for a complete system of reactive events and message dispatch.

Provides extra methods to LINQ to Objects.

One framework for creating powerful cross-platform games

FNA is an XNA4 reimplementation that focuses solely on developing a fully accurate XNA4 runtime for the desktop

Duality is a 2D game development framework. Focused on modularity, comes with a visual editor.

Nez is a free 2D-focused framework that works with MonoGame and FNA

BEPUphysics is a pure C# 3D physics library

A 2D application/game written with amazing games in mind.

A port of Recast & Detour, navigation mesh toolset for games, Unity3D, servers, C#

Foster is a small cross-platform 2D game framework in C#.

High-performance C# ECS with simple API. Supports .NET, WASM/WebAssembly, Native AOT, Unity, Godot, MonoGame, ...

A C# port of Box2D, a 2D physics engine for games, servers, and Unity3D

A .NET GIS solution that is fast and reliable for the .NET platform

.Net library for GeoJSON types & corresponding Json.Net (de)serializers

Easily parse or convert coordinate formats and calculate location based solar/lunar information.

.Net library for Digital Elevation Models, allows 3D terrain generation in glTF / STL format.

Git hooks made easy with Husky.Net internal task runner, You can use it to lint your commit messages, run tests, lint code, etc... when you commit or push. supports C# scripts, gitflow hooks, Multiple file states (staged, lastCommit, glob)

GitExtensions is a shell extension, a Visual Studio 2008/2010/2012/2013 plugin and a standalone Git repository tool. https://gitextensions.github.io/

Generate a Semantic Version Number based on the state of your Git repository

LibGit2Sharp brings all the might and speed of libgit2, a native Git implementation, to the managed world of .NET and Mono.

A PowerShell environment for Git

Helps solving issues of credentials

The Open Toolkit is an advanced, low-level C# library that wraps OpenGL, OpenCL and OpenAL

A cross-platform, high-performance, low-level .NET Standard wrapper for many advanced APIs such as OpenGL, OpenCL, OpenAL, OpenXR, Assimp, GLFW, as well as many others. In addition to wrapping over Native APIs, it also comes with its own Windowing and Input abstraction. This makes game and application development with Silk.NET a breeze, and has pretty much everything a 3D application developer would need.

A low-level, portable graphics and compute library for .NET

.NET library to create vector graphics and text, and then export it to PDF, SVG and raster image formats.

Helix Toolkit is a collection of 3D components for .NET

Simple, flexible, interactive & powerful charts, maps, and gauges for .Net. LiveCharts2 supports WPF, WinForms, Xamarin, Avalonia, WinUI, UWP.

Implementation of Facebook's GraphQL in .Net

GraphQL server compatible to all GraphQL compliant clients like Strawberry Shake, Relay, Apollo Client, and various other clients and tools.

library to build a GraphQL API on top of data model with the extensibility to easily bring multiple data sources together in the single GraphQL schema (EF is not a requirement - any ORM working with LinqProvider or an in-memory object will work).

high-performance C#-friendly GraphQL client. It supports Linq-like syntax. It doesn't require Reflection.Emit or expressions. As a result, the runtime provides performance very close to a raw HTTP call.

Complete HTML5 DOM and CSS3 OM construction

.NET port of the Ruby Less CSS lib http://www.dotlesscss.org

CSS3 parser library for C#

.NET wrapper around the libSass library with the ability to support a virtual file system

Simple REST and HTTP API client for .NET

The automatic type-safe REST library for Xamarin and .NET

An open source project based on the HttpClient. You only need to define the c# interface and modify the related features to invoke the client library of the remote http interface asynchronously.

Refit based web api client, but resilient (retry, connectivity, cache, auth, log, priority, etc...).

A fully managed and fully streamed Man-On-The-Middle library to intercept, record and alter HTTP/1.1, H2, websocket traffic over plain or secure channels.

Strongly-typed, extensible HTTP client with fluent request builder, streaming & multipart. Built on .NET's HttpRequestMessage.

A simple C# editor based on Roslyn and AvalonEdit.

A free Visual Studio Extension for MongoDB users, helping translate your code into MongoDB queries

Image processing webservice based on ASP.NET Core and ImageSharp / SkiaSharp / SvgNet / DocNET

Fully managed cross-platform library for processing of image files.

High-performance image processing pipeline for .NET, focused on making complex imaging tasks simple.

Extracts Exif, IPTC, XMP, ICC and other metadata from image files.

.NET wrapper for the ImageMagick library.

Cross platform wrapper of OpenCV for .NET Framework.

Cross-platform (Windows/macOS/Linux) image viewer which supports reading raw Luminance/YUV/RGB/ARGB/Bayer pixels data from file and rendering it. 10/16-bit YUV and viewing image frame sequence are also supported (v1.99+).

Open source .NET library for working with color spaces.

Colour conversion, interpolation, and comparison for .NET.

The most powerful set of tools available to create your Windows installation experience

Squirrel is both a set of tools and a library, to completely manage both installation and updating your desktop Windows application.

like yum or apt-get, but for Windows.

An unopinionated auto-update framework for desktop applications.

.NET Interactive takes the power of .NET and embeds it into your interactive experiences.

ICU MessageFormat implementation in .NET lets you write contextual UI messages (PCL library)

The most popular free tool to localize all kind of applications with resx-based resources.

Tools to surface C++ APIs to C#

Python and .NET interop framework

A library containing P/Invoke code for latest Windows OS.

This library allows your Java or .NET program to interface very easily with the Python world. It uses the Pyro protocol to call methods on remote objects.

A library that makes it easy to add scripting to your .NET applications. It currently supports JavaScript (via V8 and JScript) and VBScript.

Run .NET and Node.js code in-process on Windows, macOS, and Linux

JavaScript interpreter for .NET which provides full ECMA 5.1 compliance and can run on any .NET platform.

A implementation of the ECMAScript language and runtime. It aims to provide the best performing and most standards-compliant implementation of JavaScript for .NET.

JavaScript Runtime (Similar to NodeJS) for .NET Standard, compiles JavaScript to IL, support for many ES6 features, generators, CommonJS modules, CSX modules and expression compiler.

Cross-platform Natural Language Processing (NLP) library inspired by spaCy, with pre-trained models, out-of-the box support for training word and document embeddings, and flexible entity recognition models. Part of the SciSharp Stack

Multi-platform genetic algorithm library for .NET Core and .NET Framework. The library has several implementations of GA operators, like: selection, crossover, mutation, reinsertion and termination.

Cross-platform open-source machine learning framework which makes machine learning accessible to .NET developers.

F# type providers for accessing XML, JSON, CSV and HTML files (based on sample documents) and for accessing WorldBank data

Genetic algorithm .NET library for solving optimization problems, featuring extensible operators and adaptive strategy selection.

A fast, powerful, CommonMark compliant, extensible Markdown processor for .NET.

A complete cross-platform mail stack including IMAP, POP3, SMTP, authentication and more. Built on top of MimeKit.

A fully-featured fluent wrapper for MailKit that makes sending and receiving emails as simple as possible.

A cross-platform .NET MIME creation and parser library with support for S/MIME, PGP, TNEF and Unix mbox spools.

C# library that moves your stylesheets to inline style attributes, for maximum compatibility with e-mail clients.

Client for SendGrid's v3 API. Not only allows you to send emails, but also allows you to bulk import contacts, manage lists and segments, create custom fields for your lists, etc. Also includes a parser for SendGrid Webhooks.

Comprehensive math expression library with symbolic computation support including differentiation, simplification, and equation solving.

A set of tools for graph layout and viewing.

Simple and lightweight computational geometry library for .Net

Implementation of rational number arithmetic for .NET with arbitrary precision.

A simple cross platform .NET API for Intel MKL.

An open-source symbolic/computer algebra library, made primarily for C# and F#. It covers a range of features and might be considered as an alternative to SymPy in .NET.

a .NET library for rendering mathematical formulae using the LaTeX typesetting style, for the WPF framework

An advanced audio library, supporting playback/recording, decoding/encoding and processing of audio data in realtime (effects, visualizations, ...).

TagLib# (aka taglib-sharp) is a library for reading and writing metadata in media files, including video, audio, and photo formats

Xamarin bindings for libvlc, the multimedia framework powering the VLC applications made by VideoLAN.

Playback, decode and encode audio in a variety of file formats such as MP3, MP4, WAV, AIFF, Speex, etc.

.NET Standard wrapper for FFmpeg. It allows to process media without know how FFmpeg works, and can be used to pass customized arguments to FFmpeg from C# application. [$]

.NET Audio Framework for audio and MIDI playback, editing, and plugin integration.

.NET library that contains a set of markup minifiers. The objective of this project is to improve the performance of web applications by reducing the size of HTML, XHTML and XML code.

Send compressed static files to the browser without having to compress on demand, also has support for sending more advanced image formats when the browser indicates that i has support for it.

RazorKit is a collection of lightweight, fluent-style Razor HTML helpers that make it easy for developers to integrate popular JavaScript libraries into their ASP.NET applications.

Take HTML Snapshots for your Angular, Ember, Durandal or any JavaScript applications

Library to help reading and writing CSV files https://github.com/JoshClose/CsvHelper

Library to help reading and writing CSV and Flat files with zero heap allocation.

World's Fastest .NET CSV Parser. Modern, minimal, fast, zero allocation, reading and writing of separated values (csv, tsv etc.). Cross-platform, trimmable and AOT/NativeAOT compatible.

Fluent library to create table for .Net console application.

A small validation library for .NET that uses a fluent interface and lambda expressions for building validation rules.

Validot is a performance-first, compact library for advanced model validation. Using a simple declarative fluent interface, it efficiently handles classes, structs, nested members, collections, nullables, plus any relation or combination of them. It also supports translations, custom logic extensions with tests, and DI containers.

Humanizer meets all your .NET needs for manipulating and displaying strings, enums, dates, times, timespans, numbers and quantities

View SQL Server and Postgres query plans directly inside LINQPad.

Express transient-exception-handling and resilience policies such as Retry, Wait-and-Retry, Circuit Breaker, and Bulkhead Isolation in a fluent manner. Fully thread-safe and full async support. (4.0 / 4.5 / .NET Core / .NET Standard / Xamarin).

Efficient reliable UDP unicast, UDP multicast, and IPC message transport - .NET port of Aeron

TypeShape is a small, extensible F# library for practical generic programming

ByteSize is a utility class that makes byte size representation in code easier by removing ambiguity of the value being represented. ByteSize is to bytes what System.TimeSpan is to time.

a library for persisting and restoring application state (a better alternative to .settings files).

Enums.NET is a high-performance type-safe .NET enum utility library

Ultimate library for extracting metadata and downloading Youtube videos and playlists.

Generate a 'device ID' that can be used to uniquely identify a computer.

The Universal Device Detection library will parse any User Agent and detect the browser, operating system, device used (desktop, tablet, mobile, tv, cars, console, etc.), brand and model.

Extension method for StringComparer that adds support for natural sorting (e.g. "abc1", "abc2", "abc10" instead of "abc1", "abc10", "abc2").

Near-zero config .NET Core library that makes Task Scheduling, Caching, Queuing, Mailing, Event Broadcasting (and more) a breeze!

Simple build versioning for .NET, powered by Git tags

High-performance, low-allocating JSON object diff and patch extension for System.Text.Json. Support generating patch document in RFC 6902 JSON Patch format.

A command-line tool for executing C# program without a project file, and you can have your custom entry point other than Main method.

A a .NET library to run C# code in parallel on the GPU through DX12, D2D1, and dynamically generated HLSL compute and pixel shaders.

A JIT (just-in-time) compiler for high-performance GPU programs written in .Net-based languages.

The HiveMQ C# MQTT client for .NET

A high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).

A small, yet powerful framework, designed for building applications across all XAML platforms. Its strong support for MV* patterns will enable you to build your solution quickly, without the need to sacrifice code quality or testability.

Catel is an application development platform with the focus on MVVM (WPF, Silverlight, Windows Phone and WinRT) and MVC (ASP.NET MVC). The core of Catel contains an IoC container, models, validation, memento, message mediator, argument checking, etc.

An MVVM framework for .NET that integrates the Reactive Extensions (Rx) framework, enabling developers to build elegant, testable applications using WPF, Windows Store Apps, WP8 or Xamarin.

A cross-platform desktop and mobile MVVM development framework.

A lightweight Framework that helps you to create well structured WPF and UWP Applications. It supports you in applying a Layered Architecture and the Model-View-ViewModel pattern.

Cross-platform mvvm mobile development framework for WPF, Silverlight for WP7 and WP8, Mono for Android, MonoTouch for iOS, Windows Universal projects (WPA8.1 and Windows 8.1 Store apps). Makes extensive use of Portable Class Libraries (PCL) to provide maintainable cross platform C# native applications.

Minimal MVVM framework inspired by Caliburn Micro, with good documentation, high test coverage, and its own IoC container

Visual Composition framework to easily build modularized MVVM applications based on the Managed Extensibility Framework (MEF). Managed Extensibility Framework (MEF)

Framework simplifying the concept of opening dialogs from a view model when using MVVM in WPF or UWP.

Ultra fast and low latency asynchronous socket server & client C# .NET Core library with support TCP, SSL, UDP, HTTP, HTTPS, WebSocket protocols and 10K connections problem solution (NETStandard).

Fully managed, cross platform (Windows, Mac, Linux) .NET library for capturing packets from live and file based devices.

A convention-based object-object mapper in .NET. https://automapper.org

A .NET source generator for generating object mappings. No runtime reflection.

A high performance object mapper in .net

ExcelDna makes it easier to create and deploy Excel Add-Ins using C#, F# or VB .NET

ClosedXML makes it easier for developers to create Excel 2007/2010 files

OfficeIMO makes it easier for developers to create/modify Word (docx) files without having Microsoft Word or Office installed

This project is the .NET version of POI Java project at https://poi.apache.org/.

EPPlus is a .NET library that reads and writes Excel 2007/2010 files using the Open Office XML format (xlsx).

The Open XML SDK provides open-source libraries for working with Open XML Documents (DOCX, XLSX, and PPTX).

DocX is a .NET library that allows developers to manipulate Word 2007/2010/2013 files, it does not require Microsoft Word or Office to be installed.

Lightweight and fast library written in C# for reading Microsoft Excel files (2.0-2007).

.NET wrapper assemblies for Microsoft Office applications.

A fluent API for the processing of PowerPoint presentations without Microsoft Office installed.

A micro Excel helper avoids OOM and high performance to create/mapping/template-fill-data.

Web-based invoice reconciliation platform with OCR extraction and automated purchase order matching using ASP.NET Core and Azure Form Recognizer.

.NET text extraction framework supports a few file formats

Object-relational mapper that enables .NET developers to work with relational data using domain-specific objects

Use typed Exceptions for Entity Framework Core when your SQL query violates database constraints in SqlServer, MySql, PostgreSQL or SQLite

Simple library that can help to sync a large number of records in-memory into the database. Lambda Expression is supported.

Entity Framework Core Bulk Extensions for super fast (BulkCopy) CRUD ops + SaveChanges on multiple DBs: SQL, PG, My, Lite.

A simple object mapper for .NET by StackExchange

The fastest micro-ORM extension for Dapper

Dapper Query Builder using String Interpolation and Fluent API

Another ORM library supports many RDBMS including MySql, SqlServer, Sqlite, Oracle, Postgresql - NOTE: This is not affiliated with Microsoft or .NET

a convenient ORM in dotnet, supports MySql, SqlServer, PostgreSQL, Oracle, Sqlite, Firebird, 达梦, 人大金仓, 神舟通用, 翰高 and Access. - NOTE: This is not affiliated with Microsoft or .NET

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

Fluent Migrations framework for .net

The fastest LINQ database access library offering a simple, light, fast, and type-safe layer between your POCO objects and your database.

A tiny ORM-ish thing for your POCOs

Simple microORM that maps the results of a query onto a POCO object. Based on Schotime's branch of PetaPoco

Insight.Database is a fast, lightweight, micro-ORM for .NET

A hybrid ORM library for .NET.

An "Entity Framework"-like interface for MongoDB

High performane ORM for Sqlite, MySql, SqlServer, PostgreSQL & NoSQL. Provides server with REST, GraphQL & WebSocket / PubSub API.

A NuGet v3 static feed generator with support for AWS S3 and Azure Storage

A package dependency manager for .NET with support for NuGet packages and GitHub repositories. https://fsprojects.github.io/Paket/

A C# wrapper written around QPdf to allow for easy PDF manipulation that is tested for both linux and windows. QPdf is one of the only libraries capable of PDF linearization, and this wrapper ensures you keep up to date with the underlying improvements.

iText is a PDF library that allows you to CREATE, ADAPT, INSPECT and MAINTAIN documents in the Portable Document Format (PDF) [$] [Free for OSS]

A wrapper to drive the awesome pdftk binary, which can fill PDF forms, get field information, concatenate multiple documents or pages, split documents, add or replace stamps, and can attach files to or download files from pages.

Advanced C# PDF library for render, create, edit, merge, split, print, and view PDFs. Open source PDF Viewer is available on GitHub. A NuGet package is also available for easy inclusion into your projects.[$]

A simple but effective mini-profiler for ASP.NET websites

A Secure Shell (SSH) library for .NET, optimized for parallelism. Provides SSH commands, SFTP/SCP uploads and downloads, and SOCKS4/SOCKS5/HTTP proxies.

An FTP and FTPS library for .NET, optimized for speed. Provides extensive FTP commands, file uploads/downloads and FTP proxies.

A simple yet very powerful and high performant open source library for the .NET Framework to do DNS lookups.

An RPC library and framework for .NET Core. Read more about it on Docs Microsoft

gRPCurl is a command-line tool that lets you interact with gRPC servers. It's basically curl for gRPC servers.

gRPC UI is a command-line tool that lets you interact with gRPC servers via a browser. It's sort of like Postman, but for gRPC APIs instead of REST.

The Reactive Extensions (Rx) is a library for composing asynchronous and event-based programs using observable sequences and LINQ-style query operators

Reactive Extensions (Rx) for collections

A cross platform C# .NET library supporting SIP, VoIP and WebRTC.

Class library for parsing & formatting crontab expressions as well as calculating occurrences of time based on a crontab schedule

Simple task scheduler library for scheduling NCrontab-based tasks

Quartz Enterprise Scheduler .NET

This framework allows users to write long running persistent workflows in C# using the async/await capabilities.

Lightweight embeddable workflow engine

A powerful and intuitive .NET library for defining, filtering, transforming, and scheduling instant and period timelines.

Lightweight, high-performance, reflection-free job scheduler for .NET with EF Core, cron/time-based execution, custom locking, and retry support.

A Job Scheduler sitting on top of IHostedService in dotnet.

Human-readable scheduling library for .NET using natural-language expressions.

The AWS SDK for .NET enables .NET developers to easily work with Amazon Web Services

A set of PowerShell cmdlets for developers and administrators to develop, deploy and manage Microsoft Azure applications

Windows SDK for Countly analytics and marketing platform for product and marketing managers

A GitHub API client library for .NET

Official .NET SDK for the Dropbox API

SDK for the Getty Images and iStock APIs

Elasticsearch.Net & NEST

Solr client for .NET

A C#/.NET Library for sending and receiving phone calls and text messages with Twilio.

Create state machines and lightweight state machine-based workflows directly in .NET code

Jekyll-inspired static site generation for .NET

Transform ASP.NET Core web app into a static site generator.

Utility software to strong-name sign .NET assemblies, including assemblies you do not have the source code for.

list of problematic asynchronous patterns for .NET Core with an explanation of how to solve those issues

Open source template engine based on Microsoft's Razor parsing engine supporting .NET Standard 2.0

C# port of the Ruby Liquid templating language

A fast, powerful, safe and lightweight text templating language and engine for .NET

A full sized {{mustache}} like template engine with focus on extendibility.

Fluid is an open-source .NET template engine based on the Liquid template language.

A lightweight text templating library written in C# which can be a drop-in replacement for string.Format

A real .NET Handlebars engine

Simple library for checking the architecture of C# code with a fluent API.

AutoFixture is an open source framework for .NET designed to minimize the 'Arrange' phase of your unit tests

A simple and sane fake data generator for C#. Based on and ported from the famed faker.js.

Use plain C# syntax in assertions that include both the expression expression and subexpression values in the failure message.

The easy mocking library for .NET https://fakeiteasy.github.io

A set of .NET extension methods that allow you to more naturally specify the expected outcome of a TDD or BDD-style test [Source Available] [Free for OSS]

Random Testing for .NET.

Machine.Specifications (MSpec) is a context/specification framework that removes language noise and simplifies tests.

The most popular and friendly mocking framework for .NET

Very simple load testing framework for Pull and Push scenarios. It's 100% written in F# and targeting .NET Core and full .NET Framework.

A friendly substitute for .NET mocking frameworks

A unit-testing framework for all .NET languages

A library to support tests with throwaway instances of Docker containers for all compatible .NET Standard versions.

SecTester is a new tool that integrates Bright enterprise-grade scan engine directly into your integration or e2e tests. [Proprietary] [Free]

Shouldly is an assertion framework which focuses on giving great error messages when the assertion fails while being simple and terse.

A snapshot testing tool for .NET Core and .NET Framework

Mutation testing for .NET Core projects

A free, open source, community-focused unit testing tool for the .NET Framework.

Canopy is a free, open source F# web automation and testing framework

A smooth testing framework for F# with tests as values. Unit testing, property based testing, performance testing and stress testing.

Perform a deep compare of any two .NET objects using reflection. Shows the differences between the two objects.

Verification tool to enable simple approval of complex models and documents.

Random testing library for C#. Including concurrency, causal profiling, regression and performance testing.

A lightweight .NET framework that makes integration tests fully isolated by orchestrating reusable infrastructures and environments, auto-resetting between tests. TestContainers and SQL Server built-in support. Based on XUnit.

Fast and reliable multipart downloader with asynchronous progress events for .NET applications.

Blog writer which integrated with WordPress, Blogger, et. al. Open Live Writer makes it easy to write, preview, and post to your blog.

ShareX is a free and open source program that lets you capture or record any area of your screen and share it with a single press of a key. It also allows uploading images, text or other types of files to over 80 supported destinations you can choose from.

Stack Exchange's Monitoring System

API mock server with fast setup, useful to simulate HTTP responses, leveraging ASP.NET Core features, built-in fake data generation and C# scripting engine powered by Roslyn scripting API.

Papercut is an open source (.NET based) test email viewer that runs locally with a built-in SMTP server designed to receive and notify of test email messages.

Fake REST API for prototyping or as a CRUD Back End. No need to define types, uses dynamic typing. Data is stored to a single JSON file. Has authentication, WebSocket notifications, async long running operations, random generation for errors/delays and experimental GraphQL support.

A powerful tool for managing networks and troubleshoot network problems!

YARP is a reverse proxy toolkit for building fast proxy servers in .NET using the infrastructure from ASP.NET and .NET.

An opinionated code formatter for c# that is based on the Prettier printing process.

Makes life working with units of measurement just a little bit better.

A faster, better and more stable redis desktop manager [GUI client], compatible with Linux, Windows, Mac. What's more, it won't crash when loading massive keys.

A high performance multipart downloader with many features such as pause/resume support, asynchronous progress, and throttling.

Fast deep cloning library for .NET 8+. Zero-config, works out of the box.

STranslate is a ready-to-go translation ocr tool developed with WPF.

A software simulator of HSM and smartcard simulator with HTML UI, REST API and PKCS#11 interface.

Lean Engine is an open-source fully managed C# algorithmic trading engine built for desktop and cloud usage. https://www.quantconnect.com/lean/

Trading and algorithmic trading open source platform (stock markets, forex, bitcoins and options). https://stocksharp.com

Automated web testing full featured framework based on Selenium WebDriver.