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.

  • Our Free Plans just got better! | Auth0 Icon
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  • Rezku Point of Sale Icon
    Rezku Point of Sale

    Designed for Real-World Restaurant Operations

    Rezku is an all-inclusive ordering platform and management solution for all types of restaurant and bar concepts. You can now get a fully custom branded downloadable smartphone ordering app for your restaurant exclusively from Rezku.
    Learn More
  • 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: 1,114 This Week
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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: 927 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: 604 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: 167 This Week
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  • Teradata VantageCloud Enterprise is a data analytics platform for performing advanced analytics on AWS, Azure, and Google Cloud. Icon
    Teradata VantageCloud Enterprise is a data analytics platform for performing advanced analytics on AWS, Azure, and Google Cloud.

    Power faster innovation with Teradata VantageCloud

    VantageCloud is the complete cloud analytics and data platform, delivering harmonized data and Trusted AI for all. Built for performance, flexibility, and openness, VantageCloud enables organizations to unify diverse data sources, run complex analytics, and deploy AI models—all within a single, scalable platform.
    Learn More
  • 5
    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: 28 This Week
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  • 6
    [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 ==> 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 & head-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/C23 & 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: 66 This Week
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  • 7
    Windows 11 Guide

    Windows 11 Guide

    Windows Security tools, Encryption, Nextcloud, Graphics, Gaming

    Windows 11 Guide is a comprehensive, single-repository handbook for setting up and tuning a Windows 11 (and often Windows 10) desktop for real day-to-day use, covering everything from basic configuration to advanced development and gaming scenarios. It walks users through installing essential applications, configuring Windows security tools, setting up encryption and backups, and integrating productivity services like Nextcloud. The guide also dives into graphics and gaming optimizations, making it useful for both casual users and power users who want better performance and stability. For developers and technical users, it includes sections on virtualization, containers, and Windows Subsystem for Linux (WSL2), showing how to build a capable dev environment on top of Windows. The content is maintained in markdown so it is easy to read on GitHub or convert into other formats like PDF, and it is structured with clear headings so you can jump directly to the section you need.
    Downloads: 12 This Week
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  • 8
    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: 46 This Week
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  • 9
    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: 10 This Week
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  • Yeastar: Business Phone System and Unified Communications Icon
    Yeastar: Business Phone System and Unified Communications

    Go beyond just a PBX with all communications integrated as one.

    User-friendly, optimized, and scalable, the Yeastar P-Series Phone System redefines business connectivity by bringing together calling, meetings, omnichannel messaging, and integrations in one simple platform—removing the limitations of distance, platforms, and systems.
    Learn More
  • 10
    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: 9 This Week
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  • 11
    DockPanel Suite

    DockPanel Suite

    The Visual Studio inspired docking library for .NET WinForms

    Microsoft first introduced the docking panel layout in Visual Studio .NET (2002), and soon it became popular in application design. Many commercial .NET component vendors started to provide docking libraries initially, but there was no good free and open source alternative until WeiFen Luo released DockPanel Suite (DPS for short) on SourceForge.net in 2006. After an 18 month hiatus, the project has been resurrected and is now being actively developed on GitHub.
    Downloads: 9 This Week
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  • 12
    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: 38 This Week
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  • 13
    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: 7 This Week
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  • 14
    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: 6 This Week
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  • 15
    iText Community for .NET

    iText Community for .NET

    iText for .NET is the .NET version of the iText library

    iText for .NET is the .NET version of the iText library, formerly known as iTextSharp, which it replaces. iText represents the next level of SDKs for developers who want to take advantage of the benefits PDF can bring. Equipped with a better document engine, high and low-level programming capabilities and the ability to create, edit, and enhance PDFs.
    Downloads: 6 This Week
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  • 16
    C# SDL
    SDL.NET is a set of object-oriented .NET bindings for the SDL gaming library and provides high-level access to audio, keyboard, mouse, joystick, TTF fonts, various image formats, sound mixing, MPEG-1, and 2D video framebuffer.
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    Downloads: 54 This Week
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  • 17
    Discord Rich Presence

    Discord Rich Presence

    C# custom implementation for Discord Rich Presence

    This is a C# implementation of the Discord RPC library which was originally written in C++. This avoids having to use the official C++ and instead provides a managed way of using the Rich Presence within the .NET environment. While the official C++ library has been deprecated, this library has continued support and development for all your Rich Presence needs, without requiring the Game SDK.
    Downloads: 4 This Week
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  • 18
    QuestPDF

    QuestPDF

    A library that can help you with generating PDF documents

    Quickly design and generate PDF documents with an open-source, modern, and battle-tested C# library. Forget about limitations, feel confident, enjoy your task and efficiently deliver professional products. QuestPDF is a progressive library that can help you with generating PDF documents in your .NET application by offering a friendly, discoverable and predictable C# fluent API. Do you believe that creating a complete invoice document can take less than 200 lines of code? We have prepared for you a step-by-step instruction that shows every detail of this implementation and describes the best patterns and practices. This library is created specifically for designing and arranging document layouts, with full paging support. Alternative solutions, such as HTML-based converters, are not designed for this purpose and therefore are often unpredictable and do not produce desired results.
    Downloads: 4 This Week
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  • 19

    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.
    Downloads: 24 This Week
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  • 20
    Fast Artificial Neural Network Library is a free open source neural network library, which implements multilayer artificial neural networks in C with support for both fully connected and sparsely connected networks. Cross-platform execution in both fixed and floating point are supported. It includes a framework for easy handling of training data sets. It is easy to use, versatile, well documented, and fast. Bindings to more than 15 programming languages are available. An easy to read introduction article and a reference manual accompanies the library with examples and recommendations on how to use the library. Several graphical user interfaces are also available for the library.
    Downloads: 21 This Week
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  • 21
    Elsa Workflows

    Elsa Workflows

    A .NET Standard 2.0 Workflows Library

    Build workflows in code using the Workflow Builder API or as data using JSON syntax. Or use the workflow designer to design executable workflows visually. Elsa comes with a reusable dashboard component to manage workflows and activities. Run workflows from within your application using simple to use APIs. Start or resume workflows manually, or automatically by invoking triggers. Make it your own by extending the set of activities with your own. Implementing custom activities allows for powerful workflows that can be implemented with ease. Workflows can be defined using plain C# code. In addition to an increasing number of activities that you can choose from, Elsa is designed to be extensible with your own custom activities. Short-running Workflows can be useful to implement a business rules engine, while long-running workflows greatly simplify the implementation of complex processes that involve coordinating between multiple agents (users & machines).
    Downloads: 3 This Week
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  • 22
    MASA Blazor

    MASA Blazor

    Blazor UI component library based on Material Design

    Provide a standard basic component library based on Material design specifications. Provides preset components for standard scenarios such as layout, frame standard, Loading, and global exception handling. Starting from more practical scenarios, to meet the needs of more users and scenarios, and to minimize the time cost of developers. Shorten the development cycle and improve development efficiency. And provide a set of examples of Web solutions - MASA Blazor Pro has a variety of common scenes and preset layouts and other exciting content. MASA Blazor is based on the Material design specification, and each component is carefully designed, with modularity, responsiveness and excellent performance.
    Downloads: 3 This Week
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  • 23
    NetTopologySuite

    NetTopologySuite

    A .NET GIS solution that is fast and reliable for the .NET platform.

    A .NET GIS solution that is fast and reliable for the .NET platform. NetTopologySuite is a direct port of all the functionalities offered by JTS Topology Suite: NTS exposes JTS in a '.NET way', for example using Properties, Indexers, etc. The JTS Topology Suite is an API for modeling and manipulating 2-dimensional linear geometry. It provides numerous geometric predicates and functions. JTS conforms to the Simple Features Specification for SQL published by the Open GIS Consortium.
    Downloads: 3 This Week
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  • 24
    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: 3 This Week
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  • 25
    iText Core/Community

    iText Core/Community

    iText for .NET is the .NET version of the iText library

    iText Core/Community (previously known as iTextSharp) is a high-performance, battle-tested library that allows you to create, adapt, inspect, and maintain PDF documents, allowing you to add PDF functionality to your software projects with ease. It is also available for Java. For more advanced examples, refer to our Knowledge Base or the main Examples repo. You can find C# equivalents to the Java Signing examples here, though the Java code is very similar since they have the same API. Some of the output PDF files will be incorrectly displayed by the GitHub previewer, so be sure to download them to see the correct results. The iText Suite builds on over a decade of lessons learned from iText 5 (and iTextSharp) development. The latest release of iText, version 8, is a simpler, more performant and extensible library that is ready to handle the increased challenges of today's document workflows, one add-on at a time.
    Downloads: 3 This Week
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