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: 572 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: 526 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: 89 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: 75 This Week
    Last Update:
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    ReactiveUI

    ReactiveUI

    An advanced, composable, functional reactive model-view-viewmodel

    An advanced, composable, functional reactive model-view-viewmodel framework for all .NET platforms! Describe what you want, not how to do it & rejoice in the increased readability of your code. Code is communication between people, that also happens to run on a computer. If you optimise for reading by humans, then over a long time your project will end up better. Create re-usable chunks of functionality that can be seamlessly integrated into your reactive pipelines. These chunks might be widely applicable, or specific to your application. Regardless, you have the power to write and test code once, and leverage it many times over. Any device, any platform. Share business logic between your mobile and desktop applications. ReactiveUI has first class support for Xamarin Forms, Xamarin.iOS, Xamarin.Android, Xamarin.Mac, Tizen, Windows Forms, Windows Presentation Foundation (WPF), & Universal Windows Platform (UWP).
    Downloads: 48 This Week
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  • 6
    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: 43 This Week
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  • 7
    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: 42 This Week
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  • 8
    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: 41 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: 176 This Week
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    .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: 34 This Week
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  • 11
    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: 26 This Week
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  • 12
    SkiaSharp

    SkiaSharp

    SkiaSharp is a cross-platform 2D graphics API for .NET platforms

    SkiaSharp is a cross-platform 2D graphics API for .NET platforms based on Google's Skia Graphics Library. It provides a comprehensive 2D API that can be used across mobile, server and desktop models to render images. Building SkiaSharp is mostly straight forward. The main issue is the multiple dependencies for each platform. However, these are easy to install as they are found on the various websites. If you are just working on managed code, it is even easier as there mays to skip all the native builds. Because there are multiple distros of Linux, and we cannot possibly support them all, we have a separate NuGet package that will contain the supported binaries for a few distros.
    Downloads: 16 This Week
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  • 13
    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: 62 This Week
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  • 14
    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: 13 This Week
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  • 15
    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: 12 This Week
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  • 16
    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: 12 This Week
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  • 17
    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: 12 This Week
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  • 18
    STD Foundation Classes

    STD Foundation Classes

    Object oriented frameworks - PowerBuilder, PowerServer & InfoMaker!

    by Chris Pollach (http://chrispollach.blogspot.ca) A fully integrated "object oriented" set of PB Classes for the following products: PowerBuilder, PowerClient & PowerServer. The framework greatly enhances the development process by making the PowerBuilder developer significantly more productive! License: https://sourceforge.net/projects/stdfndclass/files/License (Open Source) => Updated version of the STD "Integrated" framework 2026R1 build 2026.1.0.467 was released to production on 2026-01-09. https://sourceforge.net/projects/stdfndclass/files/FrameWork/Integrated => The STD Framework "Example Apps" 2026 R1 latest builds https://chrispollach.blogspot.com/2026/03/updated.html => Updated version of the STD "Order Entry" example App 2025R2 build 2026.1.0.647 was released on 2026-04-08. https://sourceforge.net/projects/stdfndclass/files/Applications/PowerBuilder/OrderEntry
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    Downloads: 154 This Week
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  • 19
    .NET for Apache Spark

    .NET for Apache Spark

    A free, open-source, and cross-platform big data analytics framework

    .NET for Apache Spark provides high-performance APIs for using Apache Spark from C# and F#. With these .NET APIs, you can access the most popular Dataframe and SparkSQL aspects of Apache Spark, for working with structured data, and Spark Structured Streaming, for working with streaming data. .NET for Apache Spark is compliant with .NET Standard - a formal specification of .NET APIs that are common across .NET implementations. This means you can use .NET for Apache Spark anywhere you write .NET code allowing you to reuse all the knowledge, skills, code, and libraries you already have as a .NET developer. .NET for Apache Spark runs on Windows, Linux, and macOS using .NET Core, or Windows using .NET Framework. It also runs on all major cloud providers including Azure HDInsight Spark, Amazon EMR Spark, AWS & Azure Databricks.
    Downloads: 10 This Week
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  • 20
    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: 10 This Week
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  • 21
    ABP Framework

    ABP Framework

    Open source web application framework for ASP.NET core

    ABP Framework is a complete infrastructure to create modern web applications by following the best practices and conventions of software development. Rich authentication & authorization options integrated to ASP.NET Core Identity & IdentityServer4. Provides an extensible & detailed permission system. Don't repeat yourself to implement all this common stuff again & again. Focus on your business code and let ABP automate them by conventions. Easily publish & consume distributed events using built-in Distributed Event Bus with RabbitMQ integration available. Create reusable UI themes and layouts or use one of the pre-built UI themes. Automatically filter on querying from the database to easily implement patterns like soft-delete and multi-tenancy. Instead of manually writing the repeating details of bootstrap components, use ABP's tag helpers to simplify them and take advantage of the IntelliSense. Quickly build UI forms based on a C# model using the dynamic form tag helper.
    Downloads: 9 This Week
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  • 22
    Seal Report

    Seal Report

    Database Reporting Tool and Tasks (.Net)

    Seal Report is an open-source tool for the generation of daily reports from any database. It offers a complete framework for producing dynamic reports and dashboards, with a focus on simplicity and ease of use.
    Downloads: 9 This Week
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  • 23

    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.
    Downloads: 42 This Week
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  • 24
    Accord.NET Framework

    Accord.NET Framework

    Machine learning, computer vision, statistics and computing for .NET

    The Accord.NET Framework is a .NET machine learning framework combined with audio and image processing libraries completely written in C#. It is a complete framework for building production-grade computer vision, computer audition, signal processing and statistics applications even for commercial use. A comprehensive set of sample applications provide a fast start to get up and running quickly, and extensive documentation and a wiki help fill in the details. The Accord.NET project provides machine learning, statistics, artificial intelligence, computer vision and image processing methods to .NET. It can be used on Microsoft Windows, Xamarin, Unity3D, Windows Store applications, Linux or mobile. After merging with the AForge.NET project, the framework now offers a unified API for learning/training machine learning models that is both easy to use and extensible.
    Downloads: 7 This Week
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  • 25
    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: 7 This Week
    Last Update:
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