Open Source C# Libraries
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C# Libraries
View 74 business solutionsBrowse 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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MongoDB Atlas runs apps anywhereMongoDB Atlas gives you the freedom to build and run modern applications anywhere—across AWS, Azure, and Google Cloud. With global availability in over 115 regions, Atlas lets you deploy close to your users, meet compliance needs, and scale with confidence across any geography.
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ContractSafe: Contract Management SoftwareDitch those spreadsheets, shared drives & crazy-expensive solutions with too many bells & whistles. ContractSafe offers the simplest way to manage your contracts efficiently without breaking the bank.
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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. -
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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. -
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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. -
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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. -
Get full visibility and control over your tasks and projects with Wrike.Wrike offers world-class features that empower cross-functional, distributed, or growing teams take their projects from the initial request stage all the way to tracking work progress and reporting results.
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.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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QuickOpen Plugin for notepad++
plugin for notepad++
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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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. -
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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. -
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[OFFICIAL] tinyfiledialogs C C++ v3.21.3
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 -
Create stunning, professional email signatures in minutesCreate, assign and manage all your employees’ email signatures and add targeted marketing banners. Stop getting worked up about your signatures! Leverage a centralized interface to easily create and manage the email signatures of all your employees. Take advantage of each email to broadcast and amplify your brand. Letsignit helps you regain control over your digital identity. Harmonize 100% of your employee’s email signatures in just a few clicks! 121 professional emails are received and 40 are sent every day by an employee. With Letsignit, turn every email into a powerful communication opportunity: send the right message to the right person at the right time! Innovative more than tech, inspiring more than following. Authentic more than overrated, close more than "think big", trustworthy more than doubtful. Hands-on more than complex, available but yet premium, fun but yet expert.
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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. -
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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. -
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PdfPig
Read and extract text and other content from PDFs in C#
This project allows users to read and extract text and other content from PDF files. In addition the library can be used to create simple PDF documents containing text and geometrical shapes. -
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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). -
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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.
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C# Algorithms
Plug-and-play class-library project of standard data structures
A plug-and-play class-library project of standard Data Structures and Algorithms, written in C#. It contains 75+ Data Structures and Algorithms, designed as Object-Oriented isolated components. Even though this project started for educational purposes, the implemented Data Structures and Algorithms are standard, efficient, stable and tested. This is a C#.NET solution-project, and it contains three subprojects. Algorithms, a class library project which contains the Algorithms implementations. Data Structures, a class library project which contains the Data Structures implementations. Also, UnitTest, a unit-testing project for the Algorithms and Data Structures. -
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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). -
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Refit
The automatic type-safe REST library for .NET Core, Xamarin and .NET.
Refit is a library heavily inspired by Square’s Retrofit library, and it turns your REST API into a live interface. Refit currently supports the following platforms and any .NET Standard 2.0 target. Every method must have an HTTP attribute that provides the request method and relative URL. There are six built-in annotations: Get, Post, Put, Delete, Patch and Head. The relative URL of the resource is specified in the annotation. A request URL can be updated dynamically using replacement blocks and parameters on the method. A replacement block is an alphanumeric string surrounded by { and }. Parameters that are not specified as a URL substitution will automatically be used as query parameters. This is different than Retrofit, where all parameters must be explicitly specified. Round-tripping route parameter syntax: Forward slashes aren't encoded when using a double-asterisk (**) catch-all parameter syntax. -
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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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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. -
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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. -
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CliWrap
Library for interacting with command-line interfaces
CliWrap is a .NET library that provides a high-level, fluent interface for launching and managing external command-line processes in a safe and asynchronous manner. It abstracts the complexity of the native process APIs by offering a composable model for configuring commands, arguments, working directories, and stream redirection. The library emphasizes reliability and developer ergonomics, including built-in support for piping, cancellation handling, and deadlock avoidance. CliWrap is fully asynchronous and designed with immutability principles, making it well suited for modern concurrent applications. It also includes flexible mechanisms for capturing standard output and error streams, enabling advanced automation scenarios. Overall, CliWrap simplifies process orchestration in .NET applications while maintaining strong safety and performance guarantees. -
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Librelancer
A re-implementation of Freelancer
Librelancer is an open-source reimplementation of the engine behind Freelancer, the iconic 2003 space trading and combat simulation game by Microsoft. Written in C# and powered by OpenGL and modern game development practices, Librelancer faithfully replicates the original gameplay while providing a flexible codebase for modding, analysis, and future enhancements. It supports original assets and is designed to be both a preservation project and a foundation for new space simulation games inspired by Freelancer’s legacy. -
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AngleSharp
The ultimate angle brackets parser library parsing HTML5, MathML, SVG
AngleSharp follows the W3C specifications and gives you the same results as state of the art browsers. Besides the official API AngleSharp adds some useful extension methods on top. This makes working with the DOM convenient. AngleSharp integrates everything you need to explore and mutate the DOM tree. Node retrieval is straight forward by using powerful CSS query selectors. The CSS queries in AngleSharp are super fast and very simple to use. AngleSharp respects the relationship of HTML with CSS. Therefore CSS is a first class citizen in the AngleSharp eco-system. Nevertheless, it is your choice if you want to use CSS with HTML, CSS alone or if you provide your own CSS solution. AngleSharp offers a lot of extension points. One of the best possibilities is providing scripting engines. This gives you a very elegant way of using JavaScript with C# on webpages. You can even script in other languages if you want to. -
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Async MySQL Connector .NET and .NET Core
Async MySQL Connector for .NET and .NET Core
This is an ADO.NET data provider for MySQL. It provides implementations of DbConnection, DbCommand, DbDataReader, DbTransaction, the classes needed to query and update databases from managed code. This library implements true asynchronous I/O for database operations, without blocking (or using Task.Run to run synchronous methods on a background thread). This greatly improves the throughput of a web server that performs database operations. This library outperforms MySQL Connector/NET (MySql.Data) on benchmarks. This library is MIT-licensed and may be freely distributed with commercial software. Commercial software that uses Connector/NET may have to purchase a commercial license from Oracle. Fixes dozens of open bugs in Oracle’s Connector/NET; passes all ADO.NET Specification Tests. First MySQL library to support .NET Core; uses the latest .NET features. -
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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.
