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
    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: 4,996 This Week
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  • 2
    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: 372 This Week
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  • 3
    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: 123 This Week
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  • 4
    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: 82 This Week
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    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: 63 This Week
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  • 6
    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: 24 This Week
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  • 7
    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: 115 This Week
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  • 8
    .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: 20 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: 17 This Week
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  • 10
    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: 17 This Week
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  • 11
    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: 17 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: 15 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: 60 This Week
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  • 14
    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: 178 This Week
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  • 15
    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: 12 This Week
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  • 16
    .NET Multi-platform App UI

    .NET Multi-platform App UI

    .NET MAUI is the .NET Multi-platform App UI

    .NET Multi-platform App UI (.NET MAUI) is a cross-platform framework for creating mobile and desktop apps with C# and XAML. Using .NET MAUI, you can develop apps that can run on Android, iOS, iPadOS, macOS, and Windows from a single shared codebase. .NET Multi-platform App UI (.NET MAUI) is the evolution of Xamarin.Forms that expands capabilities beyond mobile Android and iOS into desktop apps for Windows and macOS. With .NET MAUI, you can build apps that perform great for any device that runs Windows, macOS, Android, & iOS from a single codebase. Coupled with Visual Studio productivity tools and emulators, .NET and Visual Studio significantly speed up the development process for building apps that target the widest possible set of devices. Use a single development stack that supports the best of breed solutions for all modern workloads with a unified SDK, base class libraries, and toolchain.
    Downloads: 10 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: 45 This Week
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  • 18
    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: 9 This Week
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  • 19
    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: 9 This Week
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  • 20
    ASP.NET Minimal APIs Made Easy

    ASP.NET Minimal APIs Made Easy

    A light-weight REST API development framework for ASP.Net 6

    It nudges you towards the REPR Design Pattern (Request-Endpoint-Response) for convenient & maintainable endpoint creation with virtually no boilerplate. Performance is on par with Minimal APIs. It's faster, uses less memory and does around 45k more requests per second than a MVC Controller in our benchmarks. Convenient business logic validation & error responses. Easy access to environment & configuration settings. Supports policy/permission/role/claim based security. In-process pub/sub event notifications (with auto discovery). Declarative security policy building (within each endpoint). Easy Server-Sent-Events for real-time data streaming. Supports any IOC container compatible with ASP.NET. Convenient integration testing (route-less & strongly-typed). Constructor & property injection of endpoint dependencies. Built-in uncaught exception handler. Easy model binding from route/query/json body/claims/forms/headers. Supports swagger/serilog/etc.
    Downloads: 8 This Week
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  • 21
    GitVersion

    GitVersion

    From git log to SemVer in no time

    GitVersion is free to use, improve, contribute and distribute. Source code is available on GitHub under MIT license. GitVersion is built for many different use-cases and workflows, so whether you use Mainline, Git Flow or GitHub Flow, GitVersion has you covered. Gitversion is highly configurable and can be made to support your specific versioning scheme, almost regardless of what it may be. Expose version variables in different formats to the tools you use. Use GitVersion locally or in a build pipeline with TeamCity, AppVeyor, Jenkins or any of the other supported build servers. GitVersion is a tool that generates a Semantic Version number based on your Git history. The version number generated from GitVersion can then be used for various different purposes. GitVersion can be used in a Continuous Server pipeline to generate a version number that both labels the build itself and makes the different version variables available to the rest of the build pipeline.
    Downloads: 8 This Week
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  • 22
    Mono

    Mono

    Mono open source ECMA CLI, C# and .NET implementation

    Mono is an open‑source implementation of Microsoft's .NET Framework (ECMA‑compatible), enabling developers to build cross‑platform applications. Supported by the .NET Foundation, Mono allows .NET code to run across different operating systems. You can run the mono and mcs test suites with the command; make check. You can verify your installation by using the mono-test-install script, it can diagnose some common problems with Mono's install. Failure to follow these steps may result in a broken installation. The Mono Project (mono/mono) (‘original mono’) has been an important part of the .NET ecosystem since it was launched in 2001. Microsoft became the steward of the Mono Project when it acquired Xamarin in 2016.
    Downloads: 8 This Week
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  • 23
    CoreCLR

    CoreCLR

    Runtime for .NET Core

    CoreCLR is the runtime for .NET Core, an open source, general purpose development platform maintained by Microsoft and the .NET community. It is a cross-platform runtime for cloud, IoT, and desktop apps and includes a just-in-time compiler called RyuJIT.
    Downloads: 7 This Week
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  • 24
    Pixeval

    Pixeval

    Wow. Yet another Pixiv client!

    Pixeval is a third-party proxy-free P station client developed by me as an amateur. The UI is implemented using Windows Presentation Foundation , based on .NET Core 3.0 , and supports Windows 7-10 (planning to cancel support other than Win10), and implements most of the The browsing function and many enhancements have been made. It has been open sourced on Github based on the AGPL protocol . The project was conceived in 2018. At that time, the api of the P station was written in Java. At that time, it could also be accessed by modifying the hosts method. After that, GFW The blocking strategy was upgraded, and DNS pollution was upgraded to SNI blocking, so I went to find information to understand the different blocking levels and blocking mechanisms of GFW. I started writing this project in the second half of 2019, which took about 3 months. (Actually, the realization of this project is partly inspired by Notsfsssf.
    Downloads: 7 This Week
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  • 25
    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: 7 This Week
    Last Update:
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