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
    SharpShell

    SharpShell

    Create Windows Shell Extensions using the .NET Framework

    SharpShell is a .NET library that allows developers to create Windows Shell extensions in managed code, simplifying what is traditionally a complex and low-level development process. It enables the creation of context menu handlers, icon overlays, and other shell integrations using C# instead of native C++. The library abstracts many of the complexities of COM programming, making it more accessible to developers who are familiar with .NET. It includes templates and examples that help developers quickly get started with building shell extensions. SharpShell also provides tools for debugging and testing extensions, improving the development experience. It is widely used for creating custom integrations within the Windows Explorer environment. Overall, SharpShell simplifies the process of extending Windows functionality through managed code.
    Downloads: 4 This Week
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  • 2
    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: 4 This Week
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  • 3
    C# ECG Toolkit

    C# ECG Toolkit

    ECG Toolkit support for: SCP-ECG, DICOM, HL7 aECG, ISHNE & MUSE-XML

    C# ECG Toolkit is an open source software toolkit to convert, view and print electrocardiograms. The toolkit is developed using C# .NET Framework 2.0 and later (code also supports netstandard2.0). Support for ECG formats: SCP-ECG, DICOM, HL7 aECG, ISHNE, MUSE-XML and OmronECG.
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    Downloads: 31 This Week
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  • 4
    NHibernate
    .NET port of the excellent Java Hibernate which provides Object/Relational mapping to persist objects in a relational database.
    Downloads: 17 This Week
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  • 5
    .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: 3 This Week
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  • 6
    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: 3 This Week
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  • 7
    Microsoft Authentication Library .NET

    Microsoft Authentication Library .NET

    Microsoft Authentication Library (MSAL) for .NET

    MSAL.NET (Microsoft.Identity.Client) is an authentication library that enables you to acquire tokens from Azure AD, to access protected Web APIs (Microsoft APIs or applications registered with Azure Active Directory). MSAL.NET is available on several .NET platforms (Desktop, Universal Windows Platform, Xamarin Android, Xamarin iOS, Windows 8.1, and .NET Core). The MSAL library for .NET is part of the Microsoft identity platform for developers (formerly named Azure AD) v2.0. It enables you to acquire security tokens to call protected APIs. It uses industry-standard OAuth2 and OpenID Connect. The library also supports Azure AD B2C. Acquiring a token interactively enables the application to acquire a token after authenticating the user through an interactive sign-in. There are specificities, though depending on the platforms (Xamarin Android, Xamarin iOS, or UWP)
    Downloads: 3 This Week
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  • 8
    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: 3 This Week
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  • 9
    The PKI Framework (PKIF) is a cross-platform library for performing PKIX-compliant certificate processing. It includes support for SCVP, OCSP, CMS and Timestamps. It uses Windows CAPI, NSS or Crypto++ for cryptographic services and hardware support.
    Downloads: 79 This Week
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  • 10
    Alchemi is a .NET grid computing framework that allows you to painlessly aggregate the computing power of intranet and Internet-connected machines into a virtual supercomputer (computational grid) and to develop applications to run on the grid.
    Downloads: 41 This Week
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  • 11
    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: 9 This Week
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  • 12
    ASP.NET Boilerplate

    ASP.NET Boilerplate

    A web application framework

    ASP.NET Boilerplate is a general purpose application framework especially designed for new modern web applications. It uses already familiar tools and implements best practices around them to provide you a SOLID development experience. Provides a layered architectural model based on Domain Driven Design. Designed as modular and extensible. Provides infrastructure to build your own modules too. SaaS applications made easy! Integrated multi-tenancy from database to UI. Designed and developed DDD in mind. Provides a SOLID model for your application. Compherensive documentation and jump start tutorials. Actively developed on GitHub (MIT license) and open for contributions. Don't Repeat Yourself! ASP.NET Boilerplate automates common software development tasks by convention. You focus on your business code. Create your solution based on free or premium startup templates. Either with an Angular Single-Page Application or Classic MVC & jQuery architecture.
    Downloads: 2 This Week
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  • 13
    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: 2 This Week
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  • 14
    BotSharp

    BotSharp

    AI Multi-Agent Framework in .NET

    Conversation as a platform (CaaP) is the future, so it's perfect that we're already offering the whole toolkits to our .NET developers using the BotSharp AI BOT Platform Builder to build a CaaP. It opens up as much learning power as possible for your own robots and precisely control every step of the AI processing pipeline. BotSharp is an open source machine learning framework for AI Bot platform builder. This project involves natural language understanding, computer vision and audio processing technologies, and aims to promote the development and application of intelligent robot assistants in information systems. Out-of-the-box machine learning algorithms allow ordinary programmers to develop artificial intelligence applications faster and easier. It's written in C# running on .Net Core that is full cross-platform framework. C# is a enterprise-grade programming language which is widely used to code business logic in information management-related system.
    Downloads: 2 This Week
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  • 15
    CSCore

    CSCore

    An advanced audio library, written in C#. Provides tons of features

    An advanced audio library, written in C#. Provides tons of features. From playing/recording audio to decoding/encoding audio streams/files to processing audio data in real-time (e.g. applying custom effects during playback, creating visualizations). The possibilities are nearly unlimited. CSCore is a free .NET audio library which is completely written in C#. Although it is still a rather young project, it offers tons of features like playing or capturing audio, en- or decoding many different codecs, effects and much more! CSCore is based on a very extensible architecture that allows you to make it fit to your needs without any major effort. You can build music players, voice chats, audio recorders and so on! Supported platforms, Windows only, Linux and mac experimental. Optimized performance though the usage of CLI instructions provided by a custom post compiler.
    Downloads: 2 This Week
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  • 16
    MonoTorrent

    MonoTorrent

    The repository for MonoTorrent, a bittorrent library for .NET

    This is a list of all the BEPs which have been implemented in MonoTorrent. A full list of all available BEPs can be seen. Prioritise specific files. Selective file downloading (including the ability to not download specific files). Rarest first piece picking (takes priorisation into account). End-game mode to boost the last 1-2% of the download. Sequential downloading (for media files). Per-torrent download/upload rate limiting. Overall download/upload rate limiting. In memory cache to reduce disk reads. Auto-throttling if the download rate exceeds the piece verification/disk write rate. IPV4 connections. IPV6 connections. IP address ban lists. Creating torrents from a single file, a folder, or arbitrary files in arbitrary folders. Fast resume data can be saved/restored to avoid hashing the data every time a torrent is started. Incremental piece hashing (reduces disk reads by incrementally hashing each block in a piece as it is received).
    Downloads: 2 This Week
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  • 17
    OpenIddict

    OpenIddict

    Versatile OpenID Connect stack for ASP.NET Core and Microsoft.Owin

    OpenIddict aims at providing a versatile solution to implement OpenID Connect client, server and token validation support in any ASP.NET Core 2.1 (and higher) application. ASP.NET 4.6.1 (and higher) applications are also fully supported thanks to a native Microsoft.Owin 4.2 integration. Developers looking for a simple and turnkey solution are strongly encouraged to use OrchardCore and its OpenID module, which is based on OpenIddict, comes with sensible defaults and offers a built-in management GUI to easily register OpenID client applications. Unlike many other identity providers, OpenIddict is not a turnkey solution but a framework that requires writing custom code to be operational (typically, at least an authorization controller), making it a poor candidate for the certification program. While a reference implementation could be submitted as-is, this wouldn't guarantee that implementations deployed by OpenIddict users would be standard-compliant.
    Downloads: 2 This Week
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  • 18
    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: 2 This Week
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  • 19
    Xamarin.iOS & Xamarin.Mac

    Xamarin.iOS & Xamarin.Mac

    Bridges the worlds of .NET with the native APIs of macOS, iOS, tvOS

    Bridges the worlds of .NET with the native APIs of macOS, iOS, tvOS, and watchOS. This module is the main repository for both Xamarin.iOS and Xamarin.Mac. These SDKs allow us to create native iOS, tvOS, watchOS and macOS applications using the same UI controls we would in Objective-C and Xcode, except with the flexibility and elegance of a modern language (C#), the power of the .NET Base Class Library (BCL), and two first-class IDEs—Visual Studio for Mac and Visual Studio—at our fingertips. This repository is where we do development for the Xamarin.iOS and Xamarin.Mac SDKs. The preferred method for installing Xamarin.iOS and Mac is to use the Visual Studio installers (Windows, Mac). The team also strongly recommends using the latest Xamarin SDK and Xcode whenever possible.
    Downloads: 2 This Week
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  • 20
    codemaid

    codemaid

    CodeMaid is an open source Visual Studio extension to cleanup

    CodeMaid is an open source Visual Studio extension to cleanup and simplify our C#, C++, F#, VB, PHP, PowerShell, JSON, XAML, XML, ASP, HTML, CSS, LESS, SCSS, JavaScript and TypeScript coding. Cleanup random white space into a simple standard order. Add unspecified access modifiers. Utilize Visual Studio’s built-in formatting capabilities. Remove and sort using statements. And do it all automatically on save or on demand, from an individual file to the entire solution. Visualize and navigate through the contents of your C# and C++ files from a tree view hierarchy. Quickly switch between different sorting methods to get a better overview. Drag and drop to reorganize the code. See McCabe complexity scores and informative tooltips. Reorganize the layout of members in a C# file to follow Microsoft’s StyleCop convention, or your own preferences. Automatically generate regions to match. Run on demand or automatically during cleanup.
    Downloads: 2 This Week
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  • 21
    passcore

    passcore

    A self-service password management tool for Active Directory

    PassCore is a very simple 1-page web application written in C#, using ASP.NET Core, Material UI (React Components), and Microsoft Directory Services (Default provider). It allows users to change their Active Directory/LDAP password on their own, provided the user is not disabled. PassCore does not require any configuration, as it obtains the principal context from the current domain. I wrote this because a number of people have requested several features that the original version did not have. The original version of this tool was downloaded around 8000 times in 2.5 years. My hope is that the new version continues to be just as popular. There really is no free alternative out there (that I know of) so hopefully, this saves someone else some time and money. We recommend use the docker image and redirect the traffic to nginx.
    Downloads: 2 This Week
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  • 22

    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: 15 This Week
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  • 23
    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: 28 This Week
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  • 24
    Quartz.NET is a full-featured, open source job scheduling system written in C# for .NET platform that can be used from smallest apps to large scale enterprise systems.
    Downloads: 10 This Week
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  • 25
    File system/directory monitoring utilities with loggin and task processing support (can execute files or make a WCF service call). Multiple configuration options. Source code libraries can be used to create a custom file system monitor.
    Downloads: 7 This Week
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