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Top 23 C# .NET Projects
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Project mention: Jellyfin unauthenticated endpoints can leak data about your collection and more | news.ycombinator.com | 2025-04-23
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InfluxDB
InfluxDB – Built for High-Performance Time Series Workloads. InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.
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Project mention: File Pilot: A file explorer built for speed with a modern, robust interface | news.ycombinator.com | 2025-02-18
Another file explorer option is Files [0], that looks a lot more like the built in Explorer in Windows but with some additional features.
[0] https://files.community/
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ASP.NET Core
ASP.NET Core is a cross-platform .NET framework for building modern cloud-based web applications on Windows, Mac, or Linux.
Libuv describes itself as a multi-platform support library with a focus on asynchronous I/O. It is widely used in many web servers (e.g., Kestrel) and runtimes such as Node.js and Python (via uvloop). As of Zig 0.14.0, there is no native async I/O, so you must work directly with threads or create your own async API using OS primitives like epoll or kqueue. In many cases, you would likely choose a cross-platform library rather than implementing your own async API. That’s where using libuv, libevent, or libxev (written in Zig) becomes useful.
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Avalonia
Develop Desktop, Embedded, Mobile and WebAssembly apps with C# and XAML. The most popular .NET UI client technology
Check out https://avaloniaui.net as well. It's basically a cross-platform reimplementation of WPF. It's not quite as simple as C#+WinForms or Lazarus+LCL because you don't get drag-and-drop UI designer, and you need to write markup by hand (albeit with live preview). But unlike HTML, it's actually designed for desktop UI apps from the get go, so it's much easier to write for anything non-trivial. And you can still write "quick and dirty" GUI code by directly connecting event handlers to buttons and updating values etc in it, ignoring data bindings and other more advanced facilities.
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ILSpy
.NET Decompiler with support for PDB generation, ReadyToRun, Metadata (&more) - cross-platform!
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Introducing .NET Multi-platform App UI (MAUI)
.NET MAUI is the .NET Multi-platform App UI, a framework for building native device applications spanning mobile, tablet, and desktop.
Project mention: .NET MAUI Authentication on Windows: The OpenID Connect Challenge | dev.to | 2025-05-06You know, I'm not the only one surprised by this issue. If you take a look at the long threads around this issue, you can see many developers are complaining about the missing support for a very common feature such as authentication in Microsoft's own operating system!
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SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
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CleanArchitecture
Clean Architecture Solution Template: A proven Clean Architecture Template for ASP.NET Core 9 (by ardalis)
Looking at this, it has similar aspects as ASP.NET Core, and the same flaws as the Controller per class design used. Methods such as "create", "show" and "store" do not share a state, they shouldn't share a class either.
However, you can rectify this, by just not trying to share a class with any of those. In .NET Steve Smith, aka Ardalis shows how to do this with his Clean architecture idea [1], Idea is to make a class for each endpoint. This also makes it easier for "Update" classes to share functionality with other "Update" classes and so on.
[1]: https://github.com/ardalis/CleanArchitecture/tree/main/sampl...
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Bitwarden - Open-source password manager.
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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.
OpenRA did it better :D
If you haven't seen it yet https://www.openra.net/ is worth your time.
https://github.com/OpenRA/OpenRA
I have many fond memories of playing openra as "LAN" game on the "gaming weekends" from a few FOSS groups I've been in. Can't recommend "saturday gaming" enough to anyone involved in any foss community.
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Polly
Polly is a .NET resilience and transient-fault-handling library that allows developers to express policies such as Retry, Circuit Breaker, Timeout, Bulkhead Isolation, and Fallback in a fluent and thread-safe manner. From version 6.0.1, Polly targets .NET Standard 1.1 and 2.0+.
Project mention: How To Implement Retries and Resilience Patterns With Polly and Microsoft Resilience | dev.to | 2025-04-29Polly
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QuestPDF
Generate and edit PDF documents in your .NET applications using the open-source QuestPDF library and its C# Fluent API. Build invoices, reports and data exports with ease.
PDF (Portable Document Format) is widely used to save data or send data in a portable, secure format. When it comes to manipulating data into a PDF file or designing a document like an invoice, C# developers often turn to robust libraries. Two popular Libraries for these tasks are IronPDF and QuestPDF. In this article, we'll delve into how to use QuestPDF for HTML to PDF conversion and compare its features with those of IronPDF.
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winsw
A wrapper executable that can run any executable as a Windows service, in a permissive license.
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MonoGame: https://www.monogame.net/
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ArchiSteamFarm
C# application with primary purpose of farming Steam cards from multiple accounts simultaneously.
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Project mention: The Windows Subsystem for Linux is now open source | news.ycombinator.com | 2025-05-19
> whereas Microsoft is actively sabotaging wine
Do you have a link to where I can read more about this? My understanding is that Microsoft saw Wine as inconsequential to their business, even offloading the Mono runtime to them [1] when they dropped support for it.
[1] https://www.mono-project.com/
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The name of the library is BenchmarkDotNet and the documentation can be found here. The only thing you have to do is:
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Project mention: Ergo: Erlang-inspired event driven actor framework in Go | news.ycombinator.com | 2024-09-12
No per-process GC (still very configurable unlike the one here) but for hot-reload, if you don't mind completely different language, there are https://github.com/akkadotnet/akka.net and https://github.com/dotnet/orleans
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Project mention: Even Microsoft Notepad is getting AI text editing now | news.ycombinator.com | 2024-11-07
> The reliance on crusty old ass applications like those on Windows is actually kinda depressing.
macOS is the most consistent OS and Windows 11 the least [1]. With the exception of IrfanView I find neither of those apps particularly crusty though. There's https://imageglass.org
I personally moved from macOS to KDE Plasma and I'm a happy camper as long as I stay with Plasma/Qt apps.
[1] https://ntdev.blog/2021/02/06/state-of-the-windows-how-many-...
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This is fascinating. I was just playing around with this pretty printing library in .net and I wondered how security critical such a thing was, and whether or not it could be trusted.
https://spectreconsole.net/
Things like this make me a little more cautious about standard out in general! More research to do.
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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# .NET discussion
C# .NET related posts
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.NET Team Experimenting with AI-Generated PRs
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My new hobby: watching AI slowly drive Microsoft employees insane
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AI creating dotnet PRs: Implement CompareInfo.Version for hybrid globalization
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Using Open AI with JS File API
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Web App Generator
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A Pauseless Garbage Collector for .NET
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Would you use a CRUD code generator for a disk based database?
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A note from our sponsor - InfluxDB
www.influxdata.com | 22 May 2025
Index
What are some of the best open-source .NET projects in C#? This list will help you:
| # | Project | Stars |
|---|---|---|
| 1 | Jellyfin | 39,583 |
| 2 | Files | 37,106 |
| 3 | ASP.NET Core | 36,615 |
| 4 | Avalonia | 27,650 |
| 5 | ILSpy | 22,936 |
| 6 | Introducing .NET Multi-platform App UI (MAUI) | 22,671 |
| 7 | SteamTools | 22,074 |
| 8 | CleanArchitecture | 17,053 |
| 9 | Bitwarden | 16,552 |
| 10 | .NET Runtime | 16,350 |
| 11 | OpenRA | 15,570 |
| 12 | Polly | 13,791 |
| 13 | QuestPDF | 12,856 |
| 14 | winsw | 12,809 |
| 15 | MonoGame | 12,141 |
| 16 | modular-monolith-with-ddd | 12,092 |
| 17 | ArchiSteamFarm | 11,997 |
| 18 | ASP.NET Boilerplate | 11,924 |
| 19 | Mono | 11,282 |
| 20 | BenchmarkDotNet | 10,981 |
| 21 | Orleans | 10,381 |
| 22 | ImageGlass | 10,239 |
| 23 | spectre.console | 10,172 |
Sponsored
InfluxDB – Built for High-Performance Time Series Workloads
InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.
www.influxdata.com