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: 1,830 This Week
    Last Update:
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  • 2
    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: 963 This Week
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  • 3
    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: 222 This Week
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  • 4
    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: 36 This Week
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  • 5
    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: 182 This Week
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  • 6
    [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: 137 This Week
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  • 7
    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: 111 This Week
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  • 8
    Windows UI Library

    Windows UI Library

    Windows 10 native controls and Fluent styles for your applications

    WinUI is a user interface layer that contains modern controls and styles for building Windows apps. As the native UI layer in Windows it embodies Fluent Design, giving each Windows app the polished feel that customers expect. WinUI 2 is a library of controls that provides official native Microsoft UI controls and features for Windows UWP apps. WinUI 2 can be used in any Windows 10 UWP XAML app, or in a Xamarin.Forms app running on Windows 10 using native view embedding. WinUI 3 is the next generation of the WinUI framework. It dramatically expands WinUI into a full UX framework, making WinUI available for all types of Windows apps, from Win32 to UWP, for use as the UI layer. You can build new Windows apps using WinUI 3, which ships as a part of the Windows App SDK. The latest available stable release is the Windows App SDK 0.8 (previously called Project Reunion). With this release, you can ship production Desktop apps to the Microsoft Store.
    Downloads: 20 This Week
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  • 9
    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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  • 10

    ConcatPDF

    PDF Concatenation Tool

    ConcatPDF is the tool to concatenate PDF files. It can concatenate, extract, encrypt, decrypt, configure PDF files, convert image files to PDF. GUI version and CUI version are both available. iText.NET is iText porting on .NET Framework by J#. This library allows you to generate PDF, (X)HTML, XML, RTF files on Microsoft.NET Framework including ASP.NET.
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    Downloads: 110 This Week
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  • 11
    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: 15 This Week
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  • 12
    LLM Tornado

    LLM Tornado

    The .NET library to build AI agents with 30+ built-in connectors

    LLM Tornado is a provider-agnostic .NET SDK designed to build, orchestrate, and deploy AI agents and workflows with a strong focus on flexibility and integration. It provides a unified interface that connects to more than 30 AI providers and vector databases, allowing developers to switch between models and services without rewriting application logic. The framework introduces a powerful orchestration system based on graph-like structures, where agents, tasks, and transitions can be defined and executed in parallel or sequential flows. It supports multimodal inputs and outputs, including text, images, audio, and documents, making it suitable for a wide range of AI applications. LLMTornado also integrates advanced protocols such as Model Context Protocol and agent-to-agent communication, enabling complex interactions between systems. With built-in support for local deployments, enterprise guardrails, and observability features.
    Downloads: 12 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: 10 This Week
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  • 14
    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: 36 This Week
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  • 15
    ASP.NET API Versioning

    ASP.NET API Versioning

    Libraries which add service API versioning to ASP.NET Web API

    ASP.NET API versioning gives you a powerful, but easy-to-use method for adding API versioning semantics to your new and existing REST services built with ASP.NET. The API versioning extensions define simple metadata attributes and conventions that you use to describe which API versions are implemented by your services. You don't need to learn any new routing concepts or change the way you implement your services in ASP.NET today. The default API versioning configuration is compliant with the versioning semantics outlined by the Microsoft REST Guidelines. There are also a number of customization and extension points available to support transitioning services that may not have supported API versioning in the past or supported API versioning with semantics that are different from the Microsoft REST versioning guidelines.
    Downloads: 6 This Week
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  • 16
    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: 6 This Week
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  • 17
    Discord Rich Presence

    Discord Rich Presence

    C# custom implementation for Discord Rich Presence

    This is a C# implementation of the Discord RPC library which was originally written in C++. This avoids having to use the official C++ and instead provides a managed way of using the Rich Presence within the .NET environment. While the official C++ library has been deprecated, this library has continued support and development for all your Rich Presence needs, without requiring the Game SDK.
    Downloads: 6 This Week
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  • 18
    Fast Artificial Neural Network Library is a free open source neural network library, which implements multilayer artificial neural networks in C with support for both fully connected and sparsely connected networks. Cross-platform execution in both fixed and floating point are supported. It includes a framework for easy handling of training data sets. It is easy to use, versatile, well documented, and fast. Bindings to more than 15 programming languages are available. An easy to read introduction article and a reference manual accompanies the library with examples and recommendations on how to use the library. Several graphical user interfaces are also available for the library.
    Downloads: 36 This Week
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  • 19
    ModernWPF UI Library

    ModernWPF UI Library

    Modern styles and controls for your WPF applications

    Modern styles and controls for your WPF applications. Modern styles and new features for the majority of the stock WPF controls. Light and dark themes that can be easily customized. A high contrast theme is also included. Additional controls to help you build modern applications. Some are ported from the Windows UI Library. Targets .NET Framework 4.5+, .NET Core 3+, and .NET 5+. Runs on Windows Vista SP2 and above.
    Downloads: 5 This Week
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  • 20
    PdfPig

    PdfPig

    Read and extract text and other content from PDFs in C#

    This project allows users to read and extract text and other content from PDF files. In addition the library can be used to create simple PDF documents containing text and geometrical shapes.
    Downloads: 5 This Week
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  • 21
    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: 5 This Week
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  • 22
    FastReport Open Source

    FastReport Open Source

    Free Open Source Reporting tool for .NET

    Free Open Source Reporting tool for .NET Core/.NET Framework that helps your application generate document-like reports.
    Downloads: 61 This Week
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  • 23
    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: 4 This Week
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  • 24
    AWS Lambda for .NET

    AWS Lambda for .NET

    Libraries, samples and tools to help .NET Core developers

    AWS Lambda for .NET is the repository that houses tools, libraries and templates to build and deploy AWS Lambda functions using the .NET ecosystem (including .NET Core and .NET 7+). It provides NuGet packages for event models (e.g., API Gateway, DynamoDB, S3), utilities such as Amazon.Lambda.Tools for CLI deployment, and Blueprints/templates to scaffold serverless .NET projects quickly. The framework supports writing functions in C# (and VB/F# where applicable), integrates with the .NET CLI and Visual Studio tooling, and allows developers to treat Lambda functions like any other managed .NET application while handling the deployment, packaging and runtime glue. Its goal is to make serverless in AWS feel natural for .NET developers—abstracting away boilerplate and letting you focus on business logic rather than deployment artifacts. It also supports advanced use cases such as .NET Core integration, source-generator annotations, and custom middleware within a function context.
    Downloads: 3 This Week
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  • 25
    Apache log4net

    Apache log4net

    Apache Log4net is a versatile, feature-rich, efficient logging API

    The Apache log4net library is a tool to help the programmer output log statements to a variety of output targets. log4net is a port of the excellent Apache log4j™ framework to the Microsoft® .NET runtime. We have kept the framework similar in spirit to the original log4j while taking advantage of new features in the .NET runtime. The log4net framework is based on Apache log4j™, The log4net framework, source code, binaries, documentation, examples and related materials are published under the terms of the Apache License. This document is an introduction to the log4net API, its unique features and design rationale. Log4net is an open source project based on the work of many authors. It allows the developer to control which log statements are output with arbitrary granularity. It is fully configurable at runtime using external configuration files.
    Downloads: 3 This Week
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