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: 358 This Week
    Last Update:
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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: 225 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: 121 This Week
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  • 4
    NBFC

    NBFC

    NoteBook FanControl

    NBFC is a cross-platform fan control service for notebooks. It comes with a powerful configuration system, which allows to adjust it to many different notebook models. Currently, there are no pre-built releases for Linux, but you can easily build NBFC yourself. In general the NBFC Wiki is the first place to go if you have any questions. If you want to build NBFC from source, the first thing you have to do is to download the source code. You can easily clone the NBFC repository via git. Make sure the Mono runtime + development tools are installed on your machine (Debian based distros: mono-complete, Arch based distros: mono). Config files are an integral part of NBFC, because they define how NBFC interacts with your notebook's embedded controller (EC). The EC, among other things, monitors your system's temperatures and controls the fan(s). It usually sits on the motherboard or is integrated into a Super I/O chip and is connected to the Southbridge via the Low Pin Count (LPC) bus.
    Downloads: 69 This Week
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  • AI-based, Comprehensive Service Management for Businesses and IT Providers Icon
    AI-based, Comprehensive Service Management for Businesses and IT Providers

    Modular solutions for change management, asset management and more

    ChangeGear provides IT staff with the functions required to manage everything from ticketing to incident, change and asset management and more. ChangeGear includes a virtual agent, self-service portals and AI-based features to support analyst and end user productivity.
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  • 5
    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: 58 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: 55 This Week
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  • 7
    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: 44 This Week
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  • 8

    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: 203 This Week
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  • 9
    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: 169 This Week
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  • Repair-CRM Icon
    Repair-CRM

    For small companies that repair and maintenance customer machines

    All-In-One Solution with an Online Booking portal for automating scheduling & dispatching to ditch paperwork and improve the productivity of your technicians!
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  • 10
    .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: 33 This Week
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  • 11
    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: 26 This Week
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  • 12
    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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  • 13
    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: 16 This Week
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  • 14
    Pokemon Unity

    Pokemon Unity

    A framework to build Pokémon RPG games

    A framework to build Pokémon RPG games. I use IIcolour Spectrum's original Pokemon Unity as a base with Herbertmilhomme's framework. So far, this project use wrapper ( Legacy <=> Framework ), and in the future, I want to remove the wrapper. This project is playable, but it has some issues and some features are disabled. Use Unity Hub or Editor to import this project's folder (/Pokemon Unity). Build and run the project. There are also demos for Windows, Linux, and Mac zipped in Releases!
    Downloads: 13 This Week
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  • 15
    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: 12 This Week
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  • 16
    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: 171 This Week
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  • 17
    FlaUI

    FlaUI

    UI automation library for .Net

    FlaUI is a .NET library which helps with automated UI testing of Windows applications (Win32, WinForms, WPF, Store Apps,...). It is based on native UI Automation libraries from Microsoft and therefore kind of a wrapper around them. FlaUI wraps almost everything from the UI Automation libraries but also provides the native objects in case someone has a special need that is not covered (yet) by FlaUI. Some ideas are copied from the UIAComWrapper project or TestStack.White but rewritten from scratch to have a clean codebase. To use FlaUI, you need to reference the appropriate assemblies. So you should decide, if you want to use UIA2 or UIA3 and install the appropriate library from NuGet. You can of course always download the source and compile it yourself. The entry point is usually an application or the desktop so you get an automation element (like a the main window of the application). On this, you can then search sub-elements and interact with them.
    Downloads: 11 This Week
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  • 18

    Okapi Framework (Old .NET version)

    See http://okapi.opentag.com/ for LATES VERSION of the Okapi Framework

    THIS VERSION ON SOURCEFORGE IS NO LONGER SUPPORTED and works only on Windows. The Okapi Framework is a set of components and tools for localization and translation tasks. THE NEWEST JAVA-BASED VERSION OF OKAPI IS AVAILABLE AT: http://okapi.opentag.com/ The new version runs on Windows, Mac, Linux, etc.
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    Downloads: 80 This Week
    Last Update:
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  • 19
    IKVM.NET is a JVM for the Microsoft .NET Framework and Mono. It can both dynamically run Java classes and can be used to convert Java jars into .NET assemblies. It also includes a port of the OpenJDK class libraries to .NET.
    Downloads: 40 This Week
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  • 20
    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: 9 This Week
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  • 21
    ChilliCream GraphQL Platform

    ChilliCream GraphQL Platform

    Welcome to the home of the Hot Chocolate GraphQL server for .NET

    Welcome to the home of the Hot Chocolate GraphQL server for .NET, the Strawberry Shake GraphQL client for .NET and Banana Cake Pop awesome Monaco-based GraphQL IDE. The ChilliCream GraphQL Platform, at its core, is a new way to create powerful Backends. HotChocolate, our .NET GraphQL server, connects any service or data source and creates a cohesive service to offer your consumers a unified API.
    Downloads: 9 This Week
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  • 22
    Json.NET

    Json.NET

    A popular high-performance JSON framework for .NET

    Serialize and deserialize any .NET object with Json.NET's powerful JSON serializer. Create, parse, query and modify JSON using Json.NET's JObject, JArray and JValue objects. Query JSON with an XPath-like syntax. 50% faster than DataContractJsonSerializer, and 250% faster than JavaScriptSerializer. Json.NET makes the simple easy and the complex possible. If you need it, Json.NET supports converting between XML and JSON. Json.NET is open source software and is completely free for commercial use. Json.NET supports Windows, MacOS, Linux, Mono, and Xamarin. Over 1 billion downloads and counting, Json.NET is the number one library on NuGet. Json.NET documentation is the first place to go for help. It includes over 100 code samples. Json.NET is open source under the MIT license and is free for commercial use.
    Downloads: 9 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
    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: 8 This Week
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  • 25
    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: 37 This Week
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