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

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  • 1
    mRemoteNG

    mRemoteNG

    mRemoteNG is the next generation of mRemote, open source

    mRemoteNG ("Multi‑Remote Next Generation") is a free, open‑source, tabbed remote connection manager for Windows. It consolidates multiple remote protocols (e.g., RDP, VNC, SSH) into a single interface, making it easier to organize and manage connections. Tabbed interface for keeping multiple sessions organized. Integrates with external credential vaults (e.g. Thycotic Secret Server) and supports dynamic host update for EC2. Supports a wide range of protocols: RDP, VNC, SSH, Telnet, HTTP/HTTPS, raw socket, PowerShell remoting.
    Downloads: 2,947 This Week
    Last Update:
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  • 2
    AssetStudio

    AssetStudio

    AssetStudio is a tool for exploring, extracting and exporting assets

    AssetStudio is a cross-platform tool for exploring, extracting, and exporting assets from Unity games—supporting assetbundles and built-in assets. It handles textures, sprites, audio, meshes, shaders, and more, exporting to formats like png, bmp, mp3, wav. The original is archived (supports Unity ≤2022.1); forks like AssetStudio2024 add support for newer Unity versions and Lua asset decompiling.
    Downloads: 593 This Week
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  • 3
    This plugin mimics the "open selected file" in PSPad. I am a PHP developer and i often see an 'require_once("../this/is/some/file.php");'. In pspad you can select the whole path (../this/is/some/file.php) and open it from the menu. Now you can do the same in notepad++. Just select the whole path and press alt+o, or use the button in the toolbar on top. It will open the file automatically. The plugin understands the relative path. The code is also available on https://bitbucket.org/sgezel/quickopenplugin
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    Downloads: 392 This Week
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  • 4
    LibUsbDotNet C# USB Library
    .NET C# USB library for WinUSB, LibUsb-Win32, and libusb-1.0. Using the common device classes, applications work with all operating systems and drivers without modification. Lots of example code. Open source software at sourceforge.net.
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    Downloads: 220 This Week
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  • 5
    Apache log4net

    Apache log4net

    Apache Log4net is a versatile, feature-rich, efficient logging API

    The Apache log4net library is a tool to help the programmer output log statements to a variety of output targets. log4net is a port of the excellent Apache log4j™ framework to the Microsoft® .NET runtime. We have kept the framework similar in spirit to the original log4j while taking advantage of new features in the .NET runtime. The log4net framework is based on Apache log4j™, The log4net framework, source code, binaries, documentation, examples and related materials are published under the terms of the Apache License. This document is an introduction to the log4net API, its unique features and design rationale. Log4net is an open source project based on the work of many authors. It allows the developer to control which log statements are output with arbitrary granularity. It is fully configurable at runtime using external configuration files.
    Downloads: 22 This Week
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  • 6
    Playnite

    Playnite

    Video game library manager with support for wide range of libraries

    Link games from Steam, Epic, Origin, GOG, Battle.net, Ubisoft Connect and other services, including games that are not installed! Playnite supports a wide variety of console emulators. Playnite's look can be fully customized, from simple color changes to complete layout re-designs. Playnite's functionality can be extended with plugins and script extensions. Fullscreen mode with full controller support is available. Playnite tracks your time in-game (any game including emulated ones). Playnite's user interface is fast and light on resources, even with large libraries. Playnite can run from portable storage without the need of installing system dependencies. No Playnite features are locked behind a paywall and the complete source code is available under the MIT license. Playnite doesn't store any user information on remote servers. All information about your library is stored locally on your PC.
    Downloads: 19 This Week
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  • 7
    PDFsharp

    PDFsharp

    PDFsharp is a .NET library for creating and modifying PDF documents.

    PDFsharp moved to https://github.com/empira/PDFsharp PDFsharp is a .NET library for creating and modifying Adobe PDF documents programmatically from any .NET language like C# or VB.NET. PDFsharp defines classes for the objects found in PDF files, so you never have to deal with IDs or references directly. The downloads include MigraDoc Foundation, a .NET library for creating documents on the fly (supports PDF and RTF). PDFsharp is the .NET library that easily creates and processes PDF documents on the fly from any .NET language. The same drawing routines can be used to create PDF documents, draw on the screen, or send output to any printer. MigraDoc Foundation is the .NET library that easily creates documents based on an object model with paragraphs, tables, styles, etc. and renders them into PDF, XPS, or RTF.
    Downloads: 84 This Week
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  • 8
    QRCoder

    QRCoder

    A pure C# Open Source QR Code implementation

    QRCoder is a simple library, written in C#.NET, which enables you to create QR codes. It hasn't any dependencies on other libraries and is available as .NET Framework and .NET Core PCL version on NuGet. Feel free to grab-up/fork the project and make it better! QRCoder is a .NET library, completely written in C#, which enables you to generate QR Codes as defined by ISO/IEC 18004. The main target of the QRCoder library is to deliver a small and easy-to-use solution, which has no dependencies to other libraries or network stacks. (Like QR Code generators which are relying on online services which makes them vulnerable/slow in some cases.) Although simplicity is one of the main goals, QRCoder is really flexible, in both "output formats" as well as in "payload types". Payload types? Yes, QRCoder brings its own "payload generator", which helps you to create a big list of different payload types to generate special QR codes like "WiFi QR Codes", "Girocodes", "SwissQRCodes" and many more.
    Downloads: 18 This Week
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  • 9
    Importer library to import assets from different common 3D file formats such as Collada, Blend, Obj, X, 3DS, LWO, MD5, MD2, MD3, MDL, MS3D and a lot of other formats. The data is stored in an own in-memory data-format, which can be easily processed. www.open3mod.com/ is a 3D model viewer and exporter based on Assimp that is also Open Source.
    Downloads: 78 This Week
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  • 10
    [OFFICIAL] tinyfiledialogs C C++ v3.21.2

    [OFFICIAL] tinyfiledialogs C C++ v3.21.2

    inputbox password WIN OSX GTK QT Console VCPKG C# Lua R Fortran Pascal

    one C/C++ file & header provides 8 functions: - beep - tray notify popup - message & question - input & password - save file - open file(s) - select folder - color picker complements OpenGL Vulkan GLFW GLUT GLUI VTK SFML TGUI SDL Ogre Unity3d ION OpenCV CeGui MathGL GLM CPW GLOW Open3D ImGui MyGui GLT NGL STB Nuklear Fenster MicroUi & GUI-less programs NO INIT NO MAIN LOOP NO LINKING NO INCLUDE win (XP to 11) ASCII MBCS UTF-8 UTF-16 (wchar_t) - native dialogs osx/unix ASCII UTF-8 - applescript kdialog zenity shanty … ° SSH console / X forwarding / waypipe Wayland ° the dialogs can be forced into console mode ° curses dialogs via Dialog.exe/Dialog (disabled by default) C89/C18 & C++98/C++23 compliant VisualStudio MinGW GCC Clang TinyCC IntelCC OWCC BCC SunCC on Windows Mac Linux Bsd Solaris Minix Raspbian Flatpak Haiku bindings: VCPKG C# R Lua Rust Haskell Java AllegroBasic Fortran Pascal D JavaScript Kotlin click tab 'Files' for prototypes
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    Downloads: 62 This Week
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  • 11
    ClashN

    ClashN

    A clash client for Windows, support Mihomo

    clashN is a Windows desktop client for the Clash networking engine, providing a graphical interface to manage proxies, rules, and profiles. It wraps the Clash core in a familiar, configurable UI so users can import subscriptions, switch nodes, and observe connections without editing YAML by hand. The app emphasizes rule-based routing, letting you combine rule providers and policy groups to steer traffic by domain, process, or destination category. System-wide proxy control, including PAC and TUN/TAP options, helps route applications that don’t natively support proxies. Logs, traffic charts, and connection inspectors make troubleshooting and optimization straightforward. For power users, granular profile editing and hot-reloading reduce the friction of iterating on configurations.
    Downloads: 6 This Week
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  • 12
    CppSharp

    CppSharp

    Tools and libraries to glue C/C++ APIs to high-level languages

    CppSharp is a tool and set of libraries that facilitates the usage of native C/C++ code with the .NET ecosystem. It consumes C/C++ header and library files and generates the necessary glue code to surface the native API as a managed API. Such an API can be used to consume an existing native library in your managed code or add managed scripting support to a native codebase. The supported target languages at present are C# and C++/CLI. It can also be used as a library to parse native code into a syntax tree with a rich declaration and type information model. Generates the glue binding code from a syntax tree of the native code. Provides APIs for parsing of C/C++ source code into a syntax tree. Mirrors the Clang's C/C++ AST and type system classes in C# APIs.
    Downloads: 6 This Week
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  • 13
    Going.Plaid

    Going.Plaid

    Plaid API .NET library

    Going.Plaid is a library for interacting with Plaid's banking APIs. See their documentation here. It is supported for .net standard 2.0, .net core 3.1, and .net 5.0+.
    Downloads: 5 This Week
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  • 14
    Pidgin

    Pidgin

    A lightweight and fast parsing library for C#

    Pidgin is a lightweight and fast parser combinator library for C#. It allows developers to construct parsers using a declarative approach, facilitating the creation of complex parsers without external tools.​
    Downloads: 5 This Week
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  • 15

    ConcatPDF

    PDF Concatenation Tool

    ConcatPDF is the tool to concatenate PDF files. It can concatenate, extract, encrypt, decrypt, configure PDF files, convert image files to PDF. GUI version and CUI version are both available. iText.NET is iText porting on .NET Framework by J#. This library allows you to generate PDF, (X)HTML, XML, RTF files on Microsoft.NET Framework including ASP.NET.
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    Downloads: 28 This Week
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  • 16
    MQTTnet

    MQTTnet

    High performance .NET library for MQTT based communication

    MQTTnet is a high-performance .NET library for MQTT-based communication. It provides an MQTT client and an MQTT server (broker) and supports the MQTT protocol up to version 5. TLS support for client and server (but not UWP servers). Extensible communication channels (e.g. In-Memory, TCP, TCP+TLS, WS). Lightweight (only the low-level implementation of MQTT, no overhead). Performance optimized (processing ~150.000 messages/second). Uniform API across all supported versions of the MQTT protocol. Tested on the local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in /Tests/MQTTnet.TestApp.NetCore. List of connected clients available. Supports connected clients with different protocol versions at the same time. Able to publish its own messages (no loopback client required). Able to receive every message (no loopback client required).
    Downloads: 4 This Week
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  • 17
    ScottPlot

    ScottPlot

    Interactive Plotting Library for .NET

    ScottPlot is a free and open-source plotting library for .NET that makes it easy to interactively display large datasets. Line plots, bar charts, pie graphs, scatter plots, and more can be created with just a few lines of code. The ScottPlot Cookbook demonstrates how to create line plots, bar charts, pie graphs, scatter plots, and more with just a few lines of code. The ScottPlot Demo is a click-to-run application that demonstrates mouse-interactive versions of every cookbook recipe. ScottPlot does not require a GUI so it can be used to create plots in cloud applications. The images below are regenerated hourly using Azure Functions to update star metrics from the GitHub API and download count from the NuGet API. The data is plotted with ScottPlot and saved as an image file in blob storage.
    Downloads: 4 This Week
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  • 18
    Windows UI Library

    Windows UI Library

    Windows 10 native controls and Fluent styles for your applications

    WinUI is a user interface layer that contains modern controls and styles for building Windows apps. As the native UI layer in Windows it embodies Fluent Design, giving each Windows app the polished feel that customers expect. WinUI 2 is a library of controls that provides official native Microsoft UI controls and features for Windows UWP apps. WinUI 2 can be used in any Windows 10 UWP XAML app, or in a Xamarin.Forms app running on Windows 10 using native view embedding. WinUI 3 is the next generation of the WinUI framework. It dramatically expands WinUI into a full UX framework, making WinUI available for all types of Windows apps, from Win32 to UWP, for use as the UI layer. You can build new Windows apps using WinUI 3, which ships as a part of the Windows App SDK. The latest available stable release is the Windows App SDK 0.8 (previously called Project Reunion). With this release, you can ship production Desktop apps to the Microsoft Store.
    Downloads: 4 This Week
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  • 19
    AWS Lambda for .NET

    AWS Lambda for .NET

    Libraries, samples and tools to help .NET Core developers

    AWS Lambda for .NET is the repository that houses tools, libraries and templates to build and deploy AWS Lambda functions using the .NET ecosystem (including .NET Core and .NET 7+). It provides NuGet packages for event models (e.g., API Gateway, DynamoDB, S3), utilities such as Amazon.Lambda.Tools for CLI deployment, and Blueprints/templates to scaffold serverless .NET projects quickly. The framework supports writing functions in C# (and VB/F# where applicable), integrates with the .NET CLI and Visual Studio tooling, and allows developers to treat Lambda functions like any other managed .NET application while handling the deployment, packaging and runtime glue. Its goal is to make serverless in AWS feel natural for .NET developers—abstracting away boilerplate and letting you focus on business logic rather than deployment artifacts. It also supports advanced use cases such as .NET Core integration, source-generator annotations, and custom middleware within a function context.
    Downloads: 3 This Week
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  • 20
    HSharp

    HSharp

    HSharp is a library used to analyze markup language like HTML

    HSharp appears to be an experimental C#/.NET project exploring higher-level abstractions or helper patterns (the naming hints at “H#” as a layer or framework on top of C#). It groups together utilities, base classes, and conventions so that common app logic can be written faster and with less boilerplate. The repo acts as a sandbox for testing these patterns in real code, which is helpful if you want to see how the author structures services, models, or infrastructure concerns. Because it’s source-first, you can cherry-pick the parts you want into your own .NET apps and ignore the rest. The idea is to make everyday C# tasks (initialization, configuration, helpers) feel more concise and expressive. Over time it can grow into a personal toolkit for the author and anyone who likes the same idioms.
    Downloads: 3 This Week
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  • 21
    OxyPlot

    OxyPlot

    A cross-platform plotting library for .NET

    OxyPlot is a cross-platform plotting library for .NET. The code is licensed under the MIT license. This is a very permissive and corporate-friendly license. See open source and tl;dr for more details. The core library is a Portable Class Library that can be used on different platforms. Custom controls are implemented for WPF, Windows 8, Windows Phone, Windows Phone Silverlight, Windows Forms, Silverlight, GTK#, Xwt, Xamarin.iOS, Xamarin.Android, Xamarin.Forms and Xamarin.Mac. OxyPlot contains many different types of axes and series. If you need some functionality that is not included in the library, you can also create a derived class and override the rendering implementation. Make sure you reference and initialize the OxyPlot platform renderers, otherwise you will see nothing. The latest pre-release packages are pushed by AppVeyor CI to myget.org. To install these packages, set the myget.org package source https://www.myget.org/F/oxyplot and remember the "-pre" flag.
    Downloads: 3 This Week
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  • 22
    XCharts

    XCharts

    A charting and data visualization library for Unity

    A charting and data visualization library for Unity. Unity data visualization chart plugin. A UGUIpowerful, easy-to-use, parameter-configurable data visualization chart plug-in. It supports ten built-in charts. A powerful, easy-to-use, configurable charting and data visualization library for Unity. Visual configuration of parameters, real-time preview of effects, and pure code drawing without additional resources. Support ten built-in charts such as line chart, column chart, pie chart, radar chart, scatter chart, heat map, ring chart, candlestick chart, polar coordinate, parallel coordinate and so on. Supports 3D column charts, funnel charts, pyramids, dashboards, water level charts, pictographic column charts, Gantt charts, rectangular tree charts and other extended charts. Line graphs such as line graphs, curve graphs, area graphs, and stepped line graphs are supported.
    Downloads: 3 This Week
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  • 23
    FastReport Open Source

    FastReport Open Source

    Free Open Source Reporting tool for .NET

    Free Open Source Reporting tool for .NET Core/.NET Framework that helps your application generate document-like reports.
    Downloads: 44 This Week
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  • 24
    WebKit .NET
    WebKit .NET is a control library wrapper for WebKit written in C#. The aim is to make it easy for users to incorporate WebKit into their .NET applications.
    Downloads: 13 This Week
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  • 25
    OpenMCDF

    OpenMCDF

    Structured Storage .net component - pure C#

    OpenMCDF is a 100% .net / C# component that allows developers to manipulate Microsoft Compound Document File Format for OLE structured storage. It supports read/write operations on streams and storages and traversal of structures tree. Development and issue tracking has moved to github platform at https://github.com/ironfede/openmcdf
    Downloads: 15 This Week
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