Browse free open source C# Libraries and projects below. Use the toggles on the left to filter open source C# Libraries by OS, license, language, programming language, and project status.

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  • 1
    mRemoteNG

    mRemoteNG

    mRemoteNG is the next generation of mRemote, open source

    mRemoteNG ("Multi‑Remote Next Generation") is a free, open‑source, tabbed remote connection manager for Windows. It consolidates multiple remote protocols (e.g., RDP, VNC, SSH) into a single interface, making it easier to organize and manage connections. Tabbed interface for keeping multiple sessions organized. Integrates with external credential vaults (e.g. Thycotic Secret Server) and supports dynamic host update for EC2. Supports a wide range of protocols: RDP, VNC, SSH, Telnet, HTTP/HTTPS, raw socket, PowerShell remoting.
    Downloads: 1,624 This Week
    Last Update:
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  • 2
    LibUsbDotNet C# USB Library
    .NET C# USB library for WinUSB, LibUsb-Win32, and libusb-1.0. Using the common device classes, applications work with all operating systems and drivers without modification. Lots of example code. Open source software at sourceforge.net.
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    Downloads: 8,918 This Week
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  • 3
    AssetStudio

    AssetStudio

    AssetStudio is a tool for exploring, extracting and exporting assets

    AssetStudio is a cross-platform tool for exploring, extracting, and exporting assets from Unity games—supporting assetbundles and built-in assets. It handles textures, sprites, audio, meshes, shaders, and more, exporting to formats like png, bmp, mp3, wav. The original is archived (supports Unity ≤2022.1); forks like AssetStudio2024 add support for newer Unity versions and Lua asset decompiling.
    Downloads: 751 This Week
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  • 4
    This plugin mimics the "open selected file" in PSPad. I am a PHP developer and i often see an 'require_once("../this/is/some/file.php");'. In pspad you can select the whole path (../this/is/some/file.php) and open it from the menu. Now you can do the same in notepad++. Just select the whole path and press alt+o, or use the button in the toolbar on top. It will open the file automatically. The plugin understands the relative path. The code is also available on https://bitbucket.org/sgezel/quickopenplugin
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    Downloads: 338 This Week
    Last Update:
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    Playnite

    Playnite

    Video game library manager with support for wide range of libraries

    Link games from Steam, Epic, Origin, GOG, Battle.net, Ubisoft Connect and other services, including games that are not installed! Playnite supports a wide variety of console emulators. Playnite's look can be fully customized, from simple color changes to complete layout re-designs. Playnite's functionality can be extended with plugins and script extensions. Fullscreen mode with full controller support is available. Playnite tracks your time in-game (any game including emulated ones). Playnite's user interface is fast and light on resources, even with large libraries. Playnite can run from portable storage without the need of installing system dependencies. No Playnite features are locked behind a paywall and the complete source code is available under the MIT license. Playnite doesn't store any user information on remote servers. All information about your library is stored locally on your PC.
    Downloads: 39 This Week
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  • 6
    QRCoder

    QRCoder

    A pure C# Open Source QR Code implementation

    QRCoder is a simple library, written in C#.NET, which enables you to create QR codes. It hasn't any dependencies on other libraries and is available as .NET Framework and .NET Core PCL version on NuGet. Feel free to grab-up/fork the project and make it better! QRCoder is a .NET library, completely written in C#, which enables you to generate QR Codes as defined by ISO/IEC 18004. The main target of the QRCoder library is to deliver a small and easy-to-use solution, which has no dependencies to other libraries or network stacks. (Like QR Code generators which are relying on online services which makes them vulnerable/slow in some cases.) Although simplicity is one of the main goals, QRCoder is really flexible, in both "output formats" as well as in "payload types". Payload types? Yes, QRCoder brings its own "payload generator", which helps you to create a big list of different payload types to generate special QR codes like "WiFi QR Codes", "Girocodes", "SwissQRCodes" and many more.
    Downloads: 22 This Week
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  • 7
    Windows 11 Guide

    Windows 11 Guide

    Windows Security tools, Encryption, Nextcloud, Graphics, Gaming

    Windows 11 Guide is a comprehensive, single-repository handbook for setting up and tuning a Windows 11 (and often Windows 10) desktop for real day-to-day use, covering everything from basic configuration to advanced development and gaming scenarios. It walks users through installing essential applications, configuring Windows security tools, setting up encryption and backups, and integrating productivity services like Nextcloud. The guide also dives into graphics and gaming optimizations, making it useful for both casual users and power users who want better performance and stability. For developers and technical users, it includes sections on virtualization, containers, and Windows Subsystem for Linux (WSL2), showing how to build a capable dev environment on top of Windows. The content is maintained in markdown so it is easy to read on GitHub or convert into other formats like PDF, and it is structured with clear headings so you can jump directly to the section you need.
    Downloads: 19 This Week
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  • 8
    [OFFICIAL] tinyfiledialogs C C++ v3.21.3

    [OFFICIAL] tinyfiledialogs C C++ v3.21.3

    inputbox password WIN OSX GTK QT Console VCPKG C# Lua R Fortran Pascal

    one C/C++ file & header ==> 8 functions: - beep - tray notify popup - message & question - input & password - save file - open file(s) - select folder - color picker complements OpenGL Vulkan GLFW GLUT GLUI VTK SFML TGUI SDL Ogre Unity3d ION OpenCV CeGui MathGL GLM CPW GLOW Open3D ImGui MyGui GLT NGL STB Nuklear Fenster MicroUi & head-less programs NO INIT NO MAIN LOOP NO LINKING NO INCLUDE win (XP to 11) ASCII MBCS UTF-8 UTF-16 (wchar_t) - native dialogs osx/unix ASCII UTF-8 - applescript kdialog zenity shanty … ° SSH console / X forwarding / waypipe Wayland ° the dialogs can be forced into console mode ° curses dialogs via Dialog.exe/Dialog (disabled by default) C89/C23 & C++98/C++23 compliant VisualStudio MinGW GCC Clang TinyCC IntelCC OWCC BCC SunCC on Windows Mac Linux Bsd Solaris Minix Raspbian Flatpak Haiku bindings: VCPKG C# R Lua Rust Haskell Java AllegroBasic Fortran Pascal D JavaScript Kotlin click tab 'Files' for prototypes
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    Downloads: 83 This Week
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  • 9
    YoutubeExplode

    YoutubeExplode

    Abstraction layer over YouTube's internal API

    YoutubeExplode is a .NET library that provides a high-level abstraction for interacting with YouTube data, enabling developers to retrieve metadata and download media streams programmatically. The project exposes a clean API that allows applications to query videos, playlists, channels, and search results without relying on the official YouTube Data API. Under the hood, the library parses raw page data and leverages reverse-engineered internal endpoints to obtain structured information and stream manifests. Developers can use it to access details such as titles, authors, durations, captions, and available media formats, as well as to download audio or video streams for further processing. The library is designed to be intuitive and cross-platform through .NET Standard compatibility, making it suitable for desktop tools, automation pipelines, and media utilities.
    Downloads: 14 This Week
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  • 10
    SFML.Net

    SFML.Net

    Official binding of SFML for .Net languages

    SFML.Net is the official .NET binding for the Simple and Fast Multimedia Library (SFML), providing C# developers with access to a powerful multimedia and game development framework. It wraps SFML’s C++ API into a user-friendly .NET interface, making it easy to build 2D games, multimedia apps, and simulations with graphics, sound, windowing, and input support. SFML.Net keeps the design idiomatic to C#, maintaining SFML's performance and portability while providing seamless integration with .NET languages like C# and F#.
    Downloads: 11 This Week
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  • 11
    PDFsharp

    PDFsharp

    PDFsharp is a .NET library for creating and modifying PDF documents.

    PDFsharp moved to https://github.com/empira/PDFsharp PDFsharp is a .NET library for creating and modifying Adobe PDF documents programmatically from any .NET language like C# or VB.NET. PDFsharp defines classes for the objects found in PDF files, so you never have to deal with IDs or references directly. The downloads include MigraDoc Foundation, a .NET library for creating documents on the fly (supports PDF and RTF). PDFsharp is the .NET library that easily creates and processes PDF documents on the fly from any .NET language. The same drawing routines can be used to create PDF documents, draw on the screen, or send output to any printer. MigraDoc Foundation is the .NET library that easily creates documents based on an object model with paragraphs, tables, styles, etc. and renders them into PDF, XPS, or RTF.
    Downloads: 50 This Week
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  • 12
    MudBlazor

    MudBlazor

    Do more with Blazor, utilizing CSS and keeping Javascript to a minimum

    Trusted by thousands of users, from hobby developers to large enterprises. Use MudBlazor to rapidly build amazing web applications without leaving your loved C# language and toolchain. We bring together everything that's required to build amazing Blazor applications that scale from desktop to mobile. Apart from the library itself we also provide templates, a learning platform, theme manager, demo and example projects as well as an online code editor integrated with our documentation and issue tracking. With more to come. We help companies build amazing apps in record time and let them focus on their business instead of buttons, MudBlazor is battle-tested and one of the fastest-improving platforms, and much more. We started MudBlazor with a simple promise, to empower the developer and fully take advantage of what Blazor offers. With MudBlazor you can create exceptional apps without the burden of mastering HTML, CSS and JS and focus your skillset on C#.
    Downloads: 9 This Week
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  • 13
    XCharts

    XCharts

    A charting and data visualization library for Unity

    A charting and data visualization library for Unity. Unity data visualization chart plugin. A UGUIpowerful, easy-to-use, parameter-configurable data visualization chart plug-in. It supports ten built-in charts. A powerful, easy-to-use, configurable charting and data visualization library for Unity. Visual configuration of parameters, real-time preview of effects, and pure code drawing without additional resources. Support ten built-in charts such as line chart, column chart, pie chart, radar chart, scatter chart, heat map, ring chart, candlestick chart, polar coordinate, parallel coordinate and so on. Supports 3D column charts, funnel charts, pyramids, dashboards, water level charts, pictographic column charts, Gantt charts, rectangular tree charts and other extended charts. Line graphs such as line graphs, curve graphs, area graphs, and stepped line graphs are supported.
    Downloads: 9 This Week
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  • 14
    AngleSharp

    AngleSharp

    The ultimate angle brackets parser library parsing HTML5, MathML, SVG

    AngleSharp follows the W3C specifications and gives you the same results as state of the art browsers. Besides the official API AngleSharp adds some useful extension methods on top. This makes working with the DOM convenient. AngleSharp integrates everything you need to explore and mutate the DOM tree. Node retrieval is straight forward by using powerful CSS query selectors. The CSS queries in AngleSharp are super fast and very simple to use. AngleSharp respects the relationship of HTML with CSS. Therefore CSS is a first class citizen in the AngleSharp eco-system. Nevertheless, it is your choice if you want to use CSS with HTML, CSS alone or if you provide your own CSS solution. AngleSharp offers a lot of extension points. One of the best possibilities is providing scripting engines. This gives you a very elegant way of using JavaScript with C# on webpages. You can even script in other languages if you want to.
    Downloads: 8 This Week
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  • 15
    Basic Computer Games

    Basic Computer Games

    An updated version of the classic "Basic Computer Games" book

    Basic Computer Games is a modern revitalization of the classic “Basic Computer Games” book’s collection of games, ported and expanded into various modern, memory-safe and scripting languages. It includes illustrative code examples of many classic games (e.g. Blackjack, Bowling) in multiple languages, with the goal of making the historical games accessible and educational in safe modern environments. Definitely use the most recent versions and features of the target language, but also try to keep the code samples simple and explainable – the goal is to teach programming in the target language, not necessarily demonstrate the cleverest one-line tricks, or big system "enterprise" coding techniques designed for thousands of lines of code.
    Downloads: 8 This Week
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  • 16
    C# Algorithms

    C# Algorithms

    Plug-and-play class-library project of standard data structures

    A plug-and-play class-library project of standard Data Structures and Algorithms, written in C#. It contains 75+ Data Structures and Algorithms, designed as Object-Oriented isolated components. Even though this project started for educational purposes, the implemented Data Structures and Algorithms are standard, efficient, stable and tested. This is a C#.NET solution-project, and it contains three subprojects. Algorithms, a class library project which contains the Algorithms implementations. Data Structures, a class library project which contains the Data Structures implementations. Also, UnitTest, a unit-testing project for the Algorithms and Data Structures.
    Downloads: 8 This Week
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  • 17
    ClashN

    ClashN

    A clash client for Windows, support Mihomo

    clashN is a Windows desktop client for the Clash networking engine, providing a graphical interface to manage proxies, rules, and profiles. It wraps the Clash core in a familiar, configurable UI so users can import subscriptions, switch nodes, and observe connections without editing YAML by hand. The app emphasizes rule-based routing, letting you combine rule providers and policy groups to steer traffic by domain, process, or destination category. System-wide proxy control, including PAC and TUN/TAP options, helps route applications that don’t natively support proxies. Logs, traffic charts, and connection inspectors make troubleshooting and optimization straightforward. For power users, granular profile editing and hot-reloading reduce the friction of iterating on configurations.
    Downloads: 8 This Week
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  • 18
    Stripe.net

    Stripe.net

    Stripe.net is a sync/async .NET 4.6.1+ client

    A .NET library to facilitate Stripe payment integration, supporting a full range of payment and subscription features for .NET applications.
    Downloads: 8 This Week
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  • 19
    Importer library to import assets from different common 3D file formats such as Collada, Blend, Obj, X, 3DS, LWO, MD5, MD2, MD3, MDL, MS3D and a lot of other formats. The data is stored in an own in-memory data-format, which can be easily processed. www.open3mod.com/ is a 3D model viewer and exporter based on Assimp that is also Open Source.
    Downloads: 35 This Week
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  • 20
    Async MySQL Connector .NET and .NET Core

    Async MySQL Connector .NET and .NET Core

    Async MySQL Connector for .NET and .NET Core

    This is an ADO.NET data provider for MySQL. It provides implementations of DbConnection, DbCommand, DbDataReader, DbTransaction, the classes needed to query and update databases from managed code. This library implements true asynchronous I/O for database operations, without blocking (or using Task.Run to run synchronous methods on a background thread). This greatly improves the throughput of a web server that performs database operations. This library outperforms MySQL Connector/NET (MySql.Data) on benchmarks. This library is MIT-licensed and may be freely distributed with commercial software. Commercial software that uses Connector/NET may have to purchase a commercial license from Oracle. Fixes dozens of open bugs in Oracle’s Connector/NET; passes all ADO.NET Specification Tests. First MySQL library to support .NET Core; uses the latest .NET features.
    Downloads: 7 This Week
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  • 21
    Librelancer

    Librelancer

    A re-implementation of Freelancer

    Librelancer is an open-source reimplementation of the engine behind Freelancer, the iconic 2003 space trading and combat simulation game by Microsoft. Written in C# and powered by OpenGL and modern game development practices, Librelancer faithfully replicates the original gameplay while providing a flexible codebase for modding, analysis, and future enhancements. It supports original assets and is designed to be both a preservation project and a foundation for new space simulation games inspired by Freelancer’s legacy.
    Downloads: 7 This Week
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  • 22
    MQTTnet

    MQTTnet

    High performance .NET library for MQTT based communication

    MQTTnet is a high-performance .NET library for MQTT-based communication. It provides an MQTT client and an MQTT server (broker) and supports the MQTT protocol up to version 5. TLS support for client and server (but not UWP servers). Extensible communication channels (e.g. In-Memory, TCP, TCP+TLS, WS). Lightweight (only the low-level implementation of MQTT, no overhead). Performance optimized (processing ~150.000 messages/second). Uniform API across all supported versions of the MQTT protocol. Tested on the local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in /Tests/MQTTnet.TestApp.NetCore. List of connected clients available. Supports connected clients with different protocol versions at the same time. Able to publish its own messages (no loopback client required). Able to receive every message (no loopback client required).
    Downloads: 7 This Week
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  • 23
    NetTopologySuite

    NetTopologySuite

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

    A .NET GIS solution that is fast and reliable for the .NET platform. NetTopologySuite is a direct port of all the functionalities offered by JTS Topology Suite: NTS exposes JTS in a '.NET way', for example using Properties, Indexers, etc. The JTS Topology Suite is an API for modeling and manipulating 2-dimensional linear geometry. It provides numerous geometric predicates and functions. JTS conforms to the Simple Features Specification for SQL published by the Open GIS Consortium.
    Downloads: 7 This Week
    Last Update:
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  • 24
    OpenAI .NET

    OpenAI .NET

    The official .NET library for the OpenAI API

    OpenAI .NET is the official client library for calling the OpenAI REST API from C# and other .NET languages, with first-class support for modern .NET patterns. It provides strongly typed clients across API areas (chat, audio, images, embeddings, moderations, batches, files, models, vector stores, responses, realtime, assistants) and works with .NET Standard 2.0 while the examples use .NET 8. You install it via NuGet and authenticate with an API key, ideally through environment variables or configuration rather than hardcoding. Every synchronous method has an async counterpart, and the library offers convenient streaming primitives for chat completions so you can process tokens as they arrive. It supports tool/function calling, structured outputs via JSON schema, audio input/output, image generation, embeddings, Whisper transcription, and assistants with retrieval augmented generation.
    Downloads: 7 This Week
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  • 25
    Veldrid

    Veldrid

    A low-level, portable graphics library for .NET

    Veldrid is a low-level, portable graphics library for .NET, providing a unified API over multiple graphics backends such as Direct3D, Vulkan, OpenGL, and Metal. It enables developers to write high-performance, cross-platform graphics applications without being tied to a specific graphics API. Veldrid is suitable for game development, simulations, and other applications requiring advanced graphics capabilities.
    Downloads: 7 This Week
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