Best Open Source csharp Libraries

A curated list of the most popular GitHub repositories tagged with csharp. Select any project to visualize its architecture and dive into the codebase using RepoMind's AI engine.

#1jellyfin/jellyfin

The Free Software Media System - Server Backend & API

49,396C#

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#2files-community/Files

A modern file manager that helps users organize their files and folders.

42,434C#

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#3ShareX/ShareX

ShareX is a free and open-source application that enables users to capture or record any area of their screen with a single keystroke. It also supports uploading images, text, and various file types to a wide range of destinations.

35,901C#

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#4doocs/leetcode

🔥LeetCode solutions in any programming language | 多种编程语言实现 LeetCode、《剑指 Offer（第 2 版）》、《程序员面试金典（第 6 版）》题解

35,786Java

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#5DevToys-app/DevToys

A Swiss Army knife for developers.

31,091C#

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#6microsoft/calculator

Windows Calculator: A simple yet powerful calculator that ships with Windows

30,870C++

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#7AvaloniaUI/Avalonia

Develop Desktop, Embedded, Mobile and WebAssembly apps with C# and XAML. The most popular .NET UI client technology

30,270C#

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#8pulumi/pulumi

Pulumi - Infrastructure as Code in any programming language 🚀

24,932Go

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#9mxgmn/WaveFunctionCollapse

Bitmap & tilemap generation from a single example with the help of ideas from quantum mechanics

24,784C#

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#10BeyondDimension/SteamTools

🛠「Watt Toolkit」是一个开源跨平台的多功能 Steam 工具箱。

24,784C#

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#11MoienTajik/AspNetCore-Developer-Roadmap

Roadmap to becoming an ASP.NET Core developer in 2026

19,549

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#12peass-ng/PEASS-ng

PEASS - Privilege Escalation Awesome Scripts SUITE (with colors)

19,507C#

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#13antlr/antlr4

ANTLR (ANother Tool for Language Recognition) is a powerful parser generator for reading, processing, executing, or translating structured text or binary files.

18,792Java

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#14rocksdanister/lively

Free and open-source software that allows users to set animated desktop wallpapers and screensavers powered by WinUI 3.

18,450C#

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#15bitwarden/server

Bitwarden infrastructure/backend (API, database, Docker, etc).

18,274C#

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#16ardalis/CleanArchitecture

Clean Architecture Solution Template: A proven Clean Architecture Template for ASP.NET Core 10

18,082C#

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#17OpenRA/OpenRA

Open Source real-time strategy game engine for early Westwood games such as Command & Conquer: Red Alert written in C# using SDL and OpenGL. Runs on Windows, Linux, *BSD and Mac OS X.

16,521C#

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#18amplication/amplication

Amplication brings order to the chaos of large-scale software development by creating Golden Paths for developers - streamlined workflows that drive consistency, enable high-quality code practices, simplify onboarding, and accelerate standardized delivery across teams.

16,003TypeScript

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#19arthurspk/guiadevbrasil

Um guia extenso de informações com um vasto conteúdo de várias áreas para ajudar, agregar conhecimento e retirar dúvidas, nesse guia você encontrará tudo que necessário para qualquer carreira relacionada a tecnologia.

15,612

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#20microsoft/mcp-for-beginners

This open-source curriculum introduces the fundamentals of Model Context Protocol (MCP) through real-world, cross-language examples in .NET, Java, TypeScript, JavaScript, Rust and Python. Designed for developers, it focuses on practical techniques for building modular, scalable, and secure AI workflows from session setup to service orchestration.

15,442Jupyter Notebook

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#21abpframework/abp

Open-source web application framework for ASP.NET Core! Offers an opinionated architecture to build enterprise software solutions with best practices on top of the .NET. Provides the fundamental infrastructure, cross-cutting-concern implementations, startup templates, application modules, UI themes, tooling and documentation.

14,277C#

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#22unoplatform/uno

Open-source platform for building cross-platform native Mobile, Web, Desktop and Embedded apps quickly. Create rich, C#/XAML, single-codebase apps from any IDE. Hot Reload included! 90m+ NuGet Downloads!!

9,855C#

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#23bchavez/Bogus

:card_index: A simple fake data generator for C#, F#, and VB.NET. Based on and ported from the famed faker.js.

9,628C#

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#24AdrienTorris/awesome-blazor

Resources for Blazor, a .NET web framework using C#/Razor and HTML that runs in the browser with WebAssembly.

9,322

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#25lepoco/wpfui

WPF UI provides the Fluent experience in your known and loved WPF framework. Intuitive design, themes, navigation and new immersive controls. All natively and effortlessly.

9,226C#

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#26AutoDarkMode/Windows-Auto-Night-Mode

Automatically switches between the dark and light theme of Windows 10 and Windows 11

9,219C#

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#27umbraco/Umbraco-CMS

Umbraco is a free and open source .NET content management system helping you deliver delightful digital experiences.

5,197C#

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#28dotnet/Silk.NET

The high-speed OpenGL, OpenCL, OpenAL, OpenXR, GLFW, SDL, Vulkan, Assimp, WebGPU, and DirectX bindings library your mother warned you about.

4,956C#

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#29dotnet/MQTTnet

MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker). The implementation is based on the documentation from http://mqtt.org/.

4,955C#

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