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

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  • 1
    BepInEx

    BepInEx

    Unity / XNA game patcher and plugin framework

    Unity / XNA game patcher and plugin framework. BepInEx is a plugin / modding framework for Unity Mono, IL2CPP, and .NET framework games (XNA, FNA, MonoGame, etc.) Stable builds are released once a new iteration of BepInEx is considered feature-complete. They have the least bugs, but some newest features might not be available. Bleeding edge builds are available on BepisBuilds. Bleeding edge builds are always the latest builds of the source code. Thus they are the opposite to stable builds: they have the newest features and bugfixes available, but usually tend to be the most buggy. Therefore you should use bleeding edge builds only if you are asked to or if you want to preview the upcoming version of BepInEx. Some games require some additional changes in order to work around specific limitations of different Unity versions.
    Downloads: 503 This Week
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  • 2
    PowerShell

    PowerShell

    Command-line shell and scripting language built on .NET

    Powershell is a cross-platform, task-based command-line shell and scripting language that helps rapidly automate tasks that manage operating systems (Linux, macOS and Windows) and processes. It works well with existing tools and is optimized for dealing with structured data, REST APIs and object models. PowerShell was developed by Microsoft as a task management and configuration management framework. Powershell is designed to let you manage computers from the command line and improve the command-line and scripting environment.
    Downloads: 285 This Week
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  • 3
    Selenium

    Selenium

    Browser automation framework and ecosystem

    Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily it is for automating web applications for testing purposes, but is certainly not limited to just that. Boring web-based administration tasks can (and should) also be automated as well. If you want to create robust, browser-based regression automation suites and tests, scale and distribute scripts across many environments, then you want to use Selenium WebDriver, a collection of language specific bindings to drive a browser - the way it is meant to be driven. If you want to create quick bug reproduction scripts, create scripts to aid in automation-aided exploratory testing, then you want to use Selenium IDE; a Chrome and Firefox add-on that will do simple record-and-playback of interactions with the browser. If you want to scale by distributing and running tests on several machines and manage multiple environments from a central point.
    Downloads: 130 This Week
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  • 4
    StabilityMatrix

    StabilityMatrix

    Multi-Platform Package Manager for Stable Diffusion

    StabilityMatrix is a project that helps organize, evaluate, and compare generative AI models and their behavior across prompts, datasets, or configuration settings. It provides a framework to run experiments systematically—capturing inputs, model configurations, outputs, and metrics—so researchers and practitioners can reason about differences in quality, robustness, and failure modes. The repository often bundles tooling for automated prompt sweeping, scoring heuristics (such as diversity, coherence, or task-specific metrics), and visualization helpers to make comparisons interpretable. This approach is useful for model selection, prompt engineering, and benchmarking new checkpoints against baseline models under reproducible conditions. By turning ad-hoc tests into tracked experiments, StabilityMatrix reduces bias, surfaces subtle regressions, and accelerates iteration when tuning generative systems.
    Downloads: 99 This Week
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  • Atera all-in-one platform IT management software with AI agents Icon
    Atera all-in-one platform IT management software with AI agents

    Ideal for internal IT departments or managed service providers (MSPs)

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  • 5
    .NET Runtime

    .NET Runtime

    Cross-platform runtime for cloud, mobile, desktop, and IoT apps

    .NET is a free, cross-platform, open source developer platform for building many different types of applications. With .NET, you can use multiple languages, editors, and libraries to build for web, mobile, desktop, games, and IoT. You can write .NET apps in C#, F#, or Visual Basic. C# is a simple, modern, object-oriented, and type-safe programming language. F# is a cross-platform, open-source, functional programming language for .NET. It also includes object-oriented and imperative programming. Visual Basic is an approachable language with a simple syntax for building type-safe, object-oriented apps. Whether you're working in C#, F#, or Visual Basic, your code will run natively on any compatible OS. Different .NET implementations handle the heavy lifting for you.
    Downloads: 80 This Week
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  • 6
    mpv.net

    mpv.net

    mpv.net is a modern media player for Windows that works just like mpv

    mpv.net is a modern desktop media player for Windows based on the popular mpv player. mpv.net is designed to be mpv compatible, almost all mpv features are available because they are all contained in libmpv, this means the official mpv manual applies to mpv.net. mpv focuses on the usage of the command line and the terminal, mpv.net retains the ability to be used from the command line and the terminal and adds a modern Windows GUI on top of it. Video output that is capable of many features loved by videophiles, such as video scaling with popular high-quality algorithms, color management, frame timing, interpolation, HDR, and more. Leverages the FFmpeg hwaccel APIs to support DXVA2 video decoding acceleration. mpv.net is based on libmpv which offers a straightforward C API that was designed from the ground up to make mpv usable as a library and facilitate easy integration into other applications. mpv is like VLC not based on DirectShow or Media Foundation.
    Downloads: 80 This Week
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  • 7
    .NET

    .NET

    This repo is the official home of .NET on GitHub

    This repository is the home of the .NET platform’s source, infrastructure, and ecosystem coordination. It serves as a “virtual monolithic repo” that aggregates the components (runtime, SDK, libraries, tools) needed to build the .NET SDK and platform. It is a central launching point for understanding, contributing to, or navigating .NET’s many open source subprojects and documentation. Contains policies, guidelines, documentation, and meta-project glue. Synchronization of subprojects into a unified view (Virtual Monolithic Repository). Issue triaging, contribution workflows, and governance linking across subrepos. Acts as an entrypoint/road map for .NET’s broad open source ecosystem.
    Downloads: 44 This Week
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  • 8
    dotnet sdk

    dotnet sdk

    Core functionality needed to create .NET Core projects

    Core functionality needed to create .NET Core projects, that is shared between Visual Studio and CLI. There are no fees or licensing costs, including for commercial use. .NET is open-source and cross-platform, with free development tools for Windows, Linux, and macOS. .NET is supported by Microsoft. Microsoft ships official releases that are built and tested on Microsoft-maintained servers in Azure and supported just like any Microsoft product. .NET is open source and we are very thankful for the many contributions it receives from the community. To test your locally built SDK, run eng\dogfood.cmd after building. That script starts a new Powershell with the environment configured to redirect SDK resolution to your build.
    Downloads: 36 This Week
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  • 9
    CefSharp

    CefSharp

    .NET bindings for the Chromium embedded framework

    CefSharp is an easy way to embed a full-featured standards-compliant web browser into your C# or VB.NET app. CefSharp has browser controls for WinForms and WPF apps, and a headless (offscreen) version for automation projects too. CefSharp is based on Chromium Embedded Framework, the open source version of Google Chrome. CefSharp embraces modern web standards, and supports HTML5, JavaScript, CSS3 and HTML5 audio/video elements. 3D content is supported via WebGL which uses OpenGL/DirectX for hardware accelerated rendering. CefSharp includes embedded modules for PDF, web page printing and the WebKit Inspector (developer tools). CefSharp has no external dependencies, and the full build of CefSharp only adds ~80 MB to your app. See the CefSharp.MinimalExample project for ready-to-compile minimal example apps built with CefSharp. Within the projects source there are more complicated example projects.
    Downloads: 31 This Week
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  • Desktop and Mobile Device Management Software Icon
    Desktop and Mobile Device Management Software

    It's a modern take on desktop management that can be scaled as per organizational needs.

    Desktop Central is a unified endpoint management (UEM) solution that helps in managing servers, laptops, desktops, smartphones, and tablets from a central location.
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  • 10
    Grassroots DICOM

    Grassroots DICOM

    Cross-platform DICOM implementation

    Grassroots DiCoM is a C++ library for DICOM medical files. It is accessible from Python, C#, Java and PHP. It supports RAW, JPEG, JPEG 2000, JPEG-LS, RLE and deflated transfer syntax. It comes with a super fast scanner implementation to quickly scan hundreds of DICOM files. It supports SCU network operations (C-ECHO, C-FIND, C-STORE, C-MOVE). PS 3.3 & 3.6 are distributed as XML files. It also provides PS 3.15 certificates and password based mecanism to anonymize and de-identify DICOM datasets.
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    Downloads: 119 This Week
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  • 11
    AvaloniaILSpy

    AvaloniaILSpy

    Avalonia-based .NET Decompiler (port of ILSpy)

    This is a cross-platform version of ILSpy built with Avalonia. Search for types/methods/properties (substring). Hyperlink-based type/method/property navigation. Extensible via MEF Extensibility (Check out TestPlugin folder). Note: This is not compatible with ILSpy Plugins. Grab artifacts from the latest master CI build. This includes Linux, Mac and Windows.
    Downloads: 19 This Week
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  • 12
    Obfuscar

    Obfuscar

    Open source obfuscation tool for .NET assemblies

    Obfuscar is an open-source .NET obfuscator released under MIT license. It provides basic obfuscation features that help secure secrets in a .NET assembly. An obfuscation tool designed for most .NET developers. Hide everything private, while keep everything public. You can achieve such simply via default settings. Hide class/method/property/event names that you don't want to expose. This is irreversible. String contents can be compressed so that end users won't easily learn them. However, this is reversible by certain tools.
    Downloads: 19 This Week
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  • 13

    Emgu CV

    Emgu CV is a cross platform .Net wrapper for OpenCV

    Emgu CV is a cross platform .Net wrapper to the OpenCV image processing library. Allowing OpenCV functions to be called from .NET compatible languages such as C#, VB, VC++, IronPython etc. The wrapper can be compiled in Mono and run on Windows, Linux, Mac OS X, iPhone, iPad and Android devices.
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    Downloads: 84 This Week
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  • 14
    CommandLineUtils

    CommandLineUtils

    Command line parsing and utilities for .NET

    CommandLineUtils is a library that helps developers implement command line applications in .NET. The primary goal of the library is to assist with parsing command line arguments and executing the correct commands related to those arguments. The library also provides various other utilities such as input helpers. This project helps you create command line applications using .NET. It simplifies parsing arguments provided on the command line, validating user inputs, and generating help text. CommandLineApplication is the main entry point for most console apps parsing. There are two primary ways to use this API, using the builder pattern and attributes. The library also includes other utilities for interaction with the console. A common scenario for options is to allow specifying a value-less option multiple times without value. The library supports counting flags by using bool[] or by checking for the number of values in Values.
    Downloads: 17 This Week
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  • 15
    MSI Downloader

    MSI Downloader

    MSI installers for a wide range of software and utilities

    MSI Downloader has been created for IT professionals who want a quick and easy method of downloading the latest MSI installers for various software. MSI installers are much easier to use for deployment using systems like Group Policy, Microsoft Deployment Toolkit (MDT) and Microsoft System Center Configuration Manager (SCCM). Some publishers happily supply MSI installers for their software, however, some are very hard to find. So this new tool will not only be providing the easy to find MSI installers, but also the hard to find ones and in some cases, the impossible to find ones - ones where we will create the MSI installers for them! The aim to keep all the MSI Installers within our utility fully up to date, but if you find something that is not, please let us know and we will correct it.
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    Downloads: 246 This Week
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  • 16
    taskt

    taskt

    Free and open-source robotic process automation (rpa)

    taskt (formerly sharpRPA) is the first truly free, easy-to-use, and open-source process automation client built on the .NET Framework in C#. taskt allows you to build and design process automation without needing to write application code. taskt allows you to automate the boring stuff and create efficienies by giving you the power to craft a digital workforce that executes and performs rule-based automation. No API? No Problem! Included is a "what you see is what you get" bot designer with dozens of automation commands. An element recorder and screen recorder is also included that can record and replay scripted automation. taskt works by allowing a bot developer to design a bot configuration known as a script. The bot configuration is then intepreted by a script engine at run-time and executes against the bot developer's selected parameter inputs. Each command contains the definitions for the required inputs as well as the required logic at run-time.
    Downloads: 13 This Week
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  • 17
    reacTIVision
    reacTIVision is a computer vision framework for the fast and robust tracking of markers attached on physical objects, and the creation of multi-touch surfaces. It was designed for the rapid development of table-based tangible user interfaces.
    Downloads: 56 This Week
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  • 18
    Brighter

    Brighter

    A framework for building messaging apps with .NET and C#

    This project is a Command Processor & Dispatcher implementation with support for task queues that can be used as a lightweight library. It can be used for implementing Ports and Adapters and CQRS (PDF) architectural styles in .NET. It can also be used in microservices architectures for decoupled communication between the services. Brighter supports Task Queues. As such it can be used to improve performance by introducing concurrency using a queue, and/or as an integration strategy between Microservices using messaging via a lightweight broker. Brighter provides support for CQRS architecture. It provides a simple library for routing commands and events to handlers. Brighter allows you to offload work from your web process to a worker process via a task queue. This allows in or out-of-process handlers. Brighter can act as a communications library for microservices, allowing commands or events to be passed between services.
    Downloads: 12 This Week
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  • 19
    RabbitMQ .NET Client

    RabbitMQ .NET Client

    RabbitMQ .NET client for .NET Standard 2.0+ and .NET 4.6.1+

    The RabbitMQ .NET client is an implementation of an AMQP 0-9-1 client library for C# (and, implicitly, other .NET languages). The library is open-source, and is dual-licensed under the the Apache License v2 and the Mozilla Public License v2.0. This means that the user can consider the library to be licensed under any of the licenses from the list above. For example, the user may choose the Apache Public License 2.0 and include this client into a commercial product. Codebases that are licensed under the GPLv2 may choose GPLv2, and so on. 6.x versions of the library require .NET 4.6.1 or a .NET Core version implementing .NET Standard 2.0. They also introduce potentially breaking public API changes covered in the changelog. 4.x and 5.x versions of the library require .NET 4.5.1 or later or .NET Core. For .NET Core users, 2.0 is the minimum supported version for 5.x series.
    Downloads: 10 This Week
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  • 20
    Windows Presentation Foundation (WPF)

    Windows Presentation Foundation (WPF)

    Framework for building Windows desktop applications

    Windows Presentation Foundation (WPF) is a UI framework for building Windows desktop applications. WPF supports a broad set of application development features, including an application model, resources, controls, graphics, layout, data binding and documents. WPF uses the Extensible Application Markup Language (XAML) to provide a declarative model for application programming. WPF applications are based on a vector graphics architecture. This enables applications to look great on high DPI monitors, as they can be infinitely scaled. WPF also includes a flexible hosting model, which makes it straightforward to host a video in a button, for example. The visual designer provided in Visual Studio makes it easy to build WPF application, with drag-in-drop and/or direct editing of XAML markup. WinForms is another UI framework for building Windows desktop applications that is supported on .NET (6.0.x/5.0.x/3.1.x). WPF and WinForms applications only run on Windows.
    Downloads: 10 This Week
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  • 21
    reko

    reko

    Reko is a binary decompiler

    Reko (Swedish: "decent, obliging") is a decompiler for machine code binaries. This project is freely available under the GNU General Public License. The project consists of front ends, core decompiler engine, and back ends to help it achieve its goals. A command line, a Windows GUI, and a ASP.NET front end exist at the time of writing. The decompiler engine receives inputs from the front ends in the form of either individual executable files or decompiler project files. Reko project files contain additional information about a binary file, helpful to the decompilation process or for formatting the output. The decompiler engine then proceeds to analyze the input binary. Reko has the ambition of supporting decompilation of various processor architectures and executable file formats with minimal user intervention. For a complete list, see the supported binaries page.
    Downloads: 9 This Week
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  • 22
    Avalonia

    Avalonia

    A cross-platform UI framework for .NET

    Avalonia is a cross-platform UI framework for dotnet, providing a flexible styling system and supporting a wide range of Operating Systems such as Windows, Linux, macOS. Avalonia is mature and production-ready. We also have in beta release support for iOS, Android and in early stages support for browsers via WASM. Avalonia is open source, free to use, and always will be. Clone the source today to dig deeper. The free VS extension provides everything needed to start, including a XAML previewer. JetBrains deep understanding of Avalonia shines through with rich Rider and R# support. Deploy to the platforms you care about with ease. Leverage existing knowledge, code and packages to kickstart your project. Get the support your project needs with one of our commercial support agreements. Help you can count on. JetBrains delivers huge productivity gains for Avalonia developers.
    Downloads: 8 This Week
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  • 23
    Paket

    Paket

    A dependency manager for .NET with support for NuGet packages and Git

    A dependency manager for .NET with support for NuGet packages and Git repositories. NuGet does not separate out the concept of transitive dependencies. If you install a package into your project and that package has further dependencies then all transitive packages are included in the packages.config. There is no way to tell which packages are only transitive dependencies. Even more importantly: If two packages reference conflicting versions of a package, NuGet will silently take the latest version (read more). You have no control over this process. Paket on the other hand maintains this information on a consistent and stable basis within the paket.lock file in the solution root. This file, together with the paket.dependencies file enables you to determine exactly what's happening with your dependencies.
    Downloads: 8 This Week
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  • 24
    opencvsharp

    opencvsharp

    OpenCV wrapper for .NET

    OpenCV wrapper for .NET. Some Docker images are provided to use OpenCvSharp with AppEngine Flexible. The native binding (libOpenCvSharpExtern) is already built in the docker image and you don't need to worry about it. OpenCvSharp won't work on Unity and Xamarin platform. For Unity, please consider using OpenCV for Unity or some other solutions. OpenCvSharp does not support CUDA. If you want to use the CUDA features, you need to customize the native bindings yourself. Objects of classes, such as Mat and MatExpr, have unmanaged resources and need to be manually released by calling the Dispose() method. Worst of all, the +, -, *, and other operators create new objects each time, and these objects need to be disposed of, or there will be memory leaks. Despite the using syntax, the code still looks very verbose.
    Downloads: 8 This Week
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  • 25
    Cofoundry

    Cofoundry

    Cofoundry is an extensible and flexible .NET Core CMS

    Cofoundry is an unobtrusive ASP.NET Core CMS focused on code-first development and user-friendly content management. Run integrated, decoupled or headless, it's your choice. Cofoundry is there when you want it and gets out of your way when you don't. Get back to writing regular .NET code you love and enjoy complete freedom with your front-end technology and designs. We understand that every application is different. Cofoundry is an adaptable framework that let's you swap in your preferred tools and scale up your architecture when you need it. DI is at the heart of Cofoundry which makes it really easy to override any implementation. Plugins are easily installed via Nuget, but it’s also simple to inject your own custom implementation. CMS administration interfaces are often built to serve both developers and content editors which leads them to be complicated and full of jargon.
    Downloads: 7 This Week
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