ReSharper brings a professional toolset for C# developers backed by over 20 years of experience, enterprise-grade security, SOC 2 compliance, and the trust of companies worldwide. Learn more →
Top 23 C# Open-Source Projects
-
Project mention: Introducing Fuse v5: Up to 7.4x Faster dotnet build and 5.7x Faster dotnet test for AI Agents | dev.to | 2026-09-30
The evals in the repository run the fuse executable the way an agent does and compare every answer with a real dotnet build or dotnet test. They ran on one Windows machine against four repositories: a small generated solution, NodaTime, Jellyfin and the .NET Community Toolkit. The times below are medians.
-
ReSharper
ReSharper is now available in VS Code and Cursor. ReSharper brings a professional toolset for C# developers backed by over 20 years of experience, enterprise-grade security, SOC 2 compliance, and the trust of companies worldwide.
-
Project mention: File Labs alternatives - Files and doublecmd | libhunt.com/r/file-labs | 2026-10-05
-
ShareX
ShareX is a free and open-source application that enables users to capture or record any area of their screen with a single keystroke. It also supports uploading images, text, and various file types to a wide range of destinations.
Project mention: OpenCapture alternatives - ShareX, flameshot, and greenshot | libhunt.com/r/OpenCapture | 2026-08-24ShareX is the reference open-source capture tool, but it's Windows-only and runs as a desktop app. OpenCapture covers the browser side of the same need — full-page web capture inside Chrome, Firefox and Edge — with the same no-upload stance.
-
-
Avalonia
Develop Desktop, Embedded, Mobile and WebAssembly apps with C# and XAML. The future of .NET UI
-
-
-
AppSignal
Monitoring that respects your time & budget. APM, error tracking, and dashboards for modern web apps. Ten-minute setup, transparent flat pricing, and support from engineers who actually use the product.
-
Project mention: 23 TypeScript Tools for Making Software Explicit in the AI Era | dev.to | 2026-08-21
Pulumi makes infrastructure resources, dependencies, and configuration explicit as typed code.
-
WaveFunctionCollapse
Bitmap & tilemap generation from a single example with the help of ideas from quantum mechanics
Project mention: Ten advances in mathematics and theoretical computer science | news.ycombinator.com | 2026-08-01No I just meant WFC as an algorithm for solving problems.
https://github.com/mxgmn/WaveFunctionCollapse
It's one of the coolest things I've ever seen.
I guess I've been pronouncing it wrong though.
-
-
awesome-dotnet-core
:honeybee: A collection of awesome .NET core libraries, tools, frameworks and software
-
Roslyn
The Roslyn .NET compiler provides C# and Visual Basic languages with rich code analysis APIs.
Project mention: I'm writing a history of Visual Basic, Chapter 1 is up | news.ycombinator.com | 2026-05-11VB.NET is open source, supports AOT, and there is little else that VB 6 does better, other than COM integration, which .NET was always a bit lower level
https://github.com/dotnet/roslyn
Now I bet what you mean is the graphical part, and yes that is only partial open source.
-
-
The public keys and ~/.ssh/config are committed as plain files, the private halves are rendered from Bitwarden at apply time and never touch git. The same mechanism fills in per-machine values — my .chezmoi.toml.tmpl pulls a few cloud subscription IDs from a Bitwarden item so the helper scripts in ~/.local/bin know which subscription to talk to without those IDs living in a public repo.
-
lively
Free and open-source software that allows users to set animated desktop wallpapers and screensavers powered by WinUI 3.
-
-
ANTLR
ANTLR (ANother Tool for Language Recognition) is a powerful parser generator for reading, processing, executing, or translating structured text or binary files.
-
CleanArchitecture
Clean Architecture Solution Template: A proven Clean Architecture Template for ASP.NET Core 10 (by ardalis)
-
OpenRA
Open Source real-time strategy game engine for early Westwood games such as Command & Conquer: Red Alert written in C# using SDL and OpenGL. Runs on Windows, Linux, *BSD and Mac OS X.
-
mcp-for-beginners
This open-source curriculum introduces the fundamentals of Model Context Protocol (MCP) through real-world, cross-language examples in .NET, Java, TypeScript, JavaScript, Rust and Python. Designed for developers, it focuses on practical techniques for building modular, scalable, and secure AI workflows from session setup to service orchestration.
MCP for Beginners (Microsoft): 13 modules on the Model Context Protocol. You build your own MCP server and client. https://github.com/microsoft/mcp-for-beginners
-
amplication
Amplication brings order to the chaos of large-scale software development by creating Golden Paths for developers - streamlined workflows that drive consistency, enable high-quality code practices, simplify onboarding, and accelerate standardized delivery across teams.
-
guiadevbrasil
Um guia extenso de informações com um vasto conteúdo de várias áreas para ajudar, agregar conhecimento e retirar dúvidas, nesse guia você encontrará tudo que necessário para qualquer carreira relacionada a tecnologia.
-
sherpa-onnx
Speech-to-text, text-to-speech, speaker diarization, speech enhancement, source separation, and VAD using next-gen Kaldi with onnxruntime without Internet connection. Support embedded systems, Android, iOS, HarmonyOS, Raspberry Pi, RISC-V, RK NPU, Axera NPU, Ascend NPU, x86_64 servers, websocket server/client, support 12 programming languages
-
SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
NOTE:
The open source projects on this list are ordered by number of github stars.
The number of mentions indicates repo mentiontions in the last 12 Months or
since we started tracking (Dec 2020).
C# discussion
C# related posts
-
Scheduled PDF and Excel report emails in ASP.NET Core with Quartz.NET
-
DotNetOpenApiExtract alternatives - Swashbuckle.AspNetCore and NSwag
3 projects | 7 Oct 2026 -
Keeping an archived 800-star Roblox tool alive: MultiAlt, in Rust and Tauri
-
Terminal.Gui – Cross Platform Terminal UI Toolkit for .NET
-
Mastering Computer Use: A Developer's Guide to Building AI-Driven Automation
-
NGB Platform 3.0.0: Architecture, Performance, and Reliability
-
Introducing Fuse v5: Up to 7.4x Faster dotnet build and 5.7x Faster dotnet test for AI Agents
-
A note from our sponsor - ReSharper
www.jetbrains.com | 8 Oct 2026
Index
What are some of the best open-source C# projects? This list will help you:
| # | Project | Stars |
|---|---|---|
| 1 | Jellyfin | 57,878 |
| 2 | Files | 45,819 |
| 3 | ShareX | 39,865 |
| 4 | DevToys | 32,063 |
| 5 | Avalonia | 31,621 |
| 6 | calculator | 31,070 |
| 7 | SteamTools | 27,018 |
| 8 | Pulumi | 25,771 |
| 9 | WaveFunctionCollapse | 25,374 |
| 10 | awesome-dotnet | 21,647 |
| 11 | awesome-dotnet-core | 21,397 |
| 12 | Roslyn | 20,702 |
| 13 | PEASS-ng | 20,605 |
| 14 | Bitwarden | 20,239 |
| 15 | lively | 19,725 |
| 16 | AspNetCore-Developer-Roadmap | 19,662 |
| 17 | ANTLR | 19,025 |
| 18 | CleanArchitecture | 18,503 |
| 19 | OpenRA | 17,483 |
| 20 | mcp-for-beginners | 17,390 |
| 21 | amplication | 16,014 |
| 22 | guiadevbrasil | 15,732 |
| 23 | sherpa-onnx | 15,109 |
Sponsored
ReSharper is now available in VS Code and Cursor
ReSharper brings a professional toolset for C# developers backed by over 20 years of experience, enterprise-grade security, SOC 2 compliance, and the trust of companies worldwide.
www.jetbrains.com