.NET 10 Preview 6 brings JIT improvements, one-shot tool execution
195 comments
·July 27, 2025jug
electroly
"dotnet tool exec" is not that feature; you're thinking of https://devblogs.microsoft.com/dotnet/announcing-dotnet-run-... which they added to "dotnet run". "dotnet run my-cool-thing.cs"
"dotnet tool exec" is so you can run third party command line tools like csharpier that previously required "dotnet tool install" before you could use them. For example, in https://csharpier.com/docs/Installation you can now simply do "dotnet tool exec csharpier". This is like "npx" in the JavaScript world.
Salgat
dotnet run *.cs is my favorite new feature for scripting. It has basically replaced powershell for me. It's trivial to script powerful operations now.
SeriousM
I guess LinqPad will lose some users to this feature.
jug
Ah yes, that's the one I was thinking of. Got confused by this article.
ZenoArrow
> I only really wish C# would’ve been directly integrated as an alternative scripting language in PowerShell.
You can embed C# in PowerShell scripts, and you have been able to do so for a long time. This webpage has a couple of examples of how this can work:
moron4hire
That's not "embedding C#". That's runtime loading of .NET assemblies, which every .NET language--including PowerShell--can do.
munchler
One of many examples of C# following in F#'s footprints years later. F# deserves a higher profile in the .NET ecosystem.
eyegor
F# has been a third class citizen for a long time... Last I heard the entire f# team was ~10 people. Pretty sure "find references" still doesn't work across c# and f# (if you call a c# method from f# or vise versa). That also means symbol renames don't work correctly.
nickpeterson
I agree, but somewhat paradoxically, F#’s lack of new features kind of becomes a feature. Have you seen the number of C# features added in the last 5-10 years? It’s crazy
tracker1
Now I'm curious if C#/.Net 10 is smart enough to ignore the shebang line. Personally, I've tended to use Deno/TS for my more advanced shell scripting... the main runtime is a single executable that works fine in user context, and dependencies can be loaded/cached at first run.
Of course, with C# as a shell script, you'd likely be limited to just in the box libraries or have to setup a project for sake of running a script, like I've had to do with Node or Python stuff.
Salgat
https://devblogs.microsoft.com/dotnet/announcing-dotnet-run-...
https://devblogs.microsoft.com/dotnet/announcing-dotnet-run-...
"dotnet run app.cs" natively supports shebang lines and nugets. The only requirement is to make sure the .net sdk is installed on your computer.
recursive
I've wanted this for a long time. After reading this link, and the MS release announcement, I still don't understand what a "tool" is, or how you can use `tool exec` to run a single *.cs file. Is there a straight-forward recipe anywhere for doing this targeted at absolute simpletons?
banashark
Well if you're familiar with the node ecosystem it's a corollary for npx/bunx/etc.
It is so that folks can build and run "tools" that are executed, utilizing the nuget ecosystem.
Relevant links in the dotnet docs (was just a quick google away):
* https://learn.microsoft.com/en-us/dotnet/core/tools/global-t...
* https://learn.microsoft.com/en-us/dotnet/core/tools/global-t...
It's actually a top-level doc section in the primary dotnet docs (https://learn.microsoft.com/en-us/dotnet/).
To boil it down: you create a console app, add a couple of attributes to the solution file (https://learn.microsoft.com/en-us/dotnet/core/tools/global-t...). Packaging and publishing to nuget (if you want to share with others) is via `dotnet pack` and `dotnet nuget push` with some flags.
I do have to say it's actually very well documented.
recursive
Sorry for being unclear. Using tools isn't my goal. I want to run a single *.cs file from the console. It may be possible to achieve this using tools, but I don't know how. I did read the resources I could find, and didn't find any information about this.
easton
The docs are terrible right now (prerelease and all that), but to get started:
1. Install the dotnet sdk preview
2. Make a .CS file with top level statements.
3. dotnet run <file>
https://devblogs.microsoft.com/dotnet/announcing-dotnet-run-...
jug
Sorry for confusing you. I can't edit the post now. The command is dotnet run script.cs. The tool stuff is about something else unrelated; NuGet installable CLI executables.
tester756
.NET was the most sane programming ecosystem that I worked in.
Great CLI, great package manager, very good stdlib, strong IDEs/Debuggers, etc.
but sadly interesting jobs like OSes, databases and compilers are way less common than in C++ world :(
reactordev
I agree. The stability comes from its ecosystem though. Enterprise Software. Where things like meticulous use of Omit and Task are common place and really REALLY bad things happen if you fuck up.
But besides that, there’s a healthy gamedev community that embraced C# early and have been using it ever since. There’s C++ MFC guys that got duped into WPF and have been supporting it ever since. Winforms devs that are still trying to make a dark mode. I’ve even seen community grass roots “I need this in Silverlight” projects take hold and become one of the largest SDKs in the world. It’s cool. It’s fun. And with AOT, it’s everywhere. C# is like that cool uncle of your Father (Java) that likes to party all night but still holds a job. Maybe someday TS.Net will exist and we’ll all be singing “Back in my day”
pjmlp
I very much doubt about TS.Net, given the rewrite in Go decision.
.NET nowadays has a serious adoption problem, and they should spend more time talking with their own colleagues at Azure, about their use of Java, Go, Rust.
thewebguyd
> .NET nowadays has a serious adoption problem
It's seriously going to make people question the future of the platform. Look at Microsoft's actions, not their words.
TS Compiler: Go New TUI Editor: Rust Winget: C++ (this would have been a great candidate for .NET)
At least PowerToys is C#.
.NET is great, but why isn't it good enough for Microsoft? The company that historically has had such a strong culture of dogfooding.
9cb14c1ec0
Not sure I agree on the adoption problem. A few medium sized client projects are nothing compared to the massive internal .NET codebases Microsoft has that run some of their largest services.
mathverse
I would not touch C# unless you are already using it. Microsoft proves over and over it cannot be trusted in what they say. Watch what they do:
- basically dont use ant UI framework they say is the future and they are not using themselves - be vary of the future of some of it stuff like C#
reactordev
I know, so sad, could have been a great opportunity.
cogman10
I blame historic microsoft for their anti-oss stance. It kneecapped the .net ecosystem for over a decade and created an attitude of "if it isn't in .NET, I won't use it".
rafaelmn
Since you mention great CLI - is there a CLI tool that is free/cross platform that works like prettier ? I found https://csharpier.com/ but have never heard of anyone using it.
Also not sure how it works with linters like roslynator or stylecop ?
This is something I miss very much when coming back from TS, other languages also have better formatters. C# is very tied to editors/IDEs which is a nightmare in teams where some people use vs/vs code/rider
Merad
Csharpier is the best option available. I've been using it for 3-4 years now and had success getting it adopted at my last two companies on greenfield projects. It's not exactly an unknown tool - nearly 2k stars on Github. But a lot old school .Net companies just don't seem to have much interest in auto formatters because they've been working without them for a long time.
If you're using csharpier you don't need to use Roslynator formatters. No issue with the analyzers package. The csharpier docs have info on what StyleCop rules need to be adjusted so they can work together. Personally I don't use StyleCop anymore as it seems to be fairly dead, and I don't really feel the need for things like enforcing file layout or naming.
Edit: Also I will add that unless the landscape has changed recently, I believe csharpier is the only C# tool that has deterministic formatting good enough to enforce code formatting checks in CI.
Cu3PO42
dotnet format [0] exists and is maintained by the .NET team. It is different from Prettier in that it is much more configurable, but it gets the job done for us. It does integrate language services and can automatically apply code fixes for custom analyzers. I have not explicitly tried roslynator or stylecop, but I suspect this would work as expected.
[0] https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-f...
jswny
The problem is that dotnet format is horribly slow. So much so that it's only useful as a precommit hook
malkia
I was not able to use (recent) dotnet-format as standalone .exe tool, also it only worked if inside an actual project with .sln/.slnx file and all that. I could not instruct it to work on single file.
rafaelmn
> It is different from Prettier in that it is much more configurable
I only tried it briefly but found it was waaay to lenient with the amount of variance in style it left unchanged (eg line breaks for function parameters) - can it get configured to produce consistent formatting like prettier ?
null
mguijarr
Hi! I use csharpier, it does the job - I included it as a preliminary check in our CI pipeline for a step of merge requests quality assessment. It is the closest tool I found, that ressembles prettier. You should definitely give it a try.
siws
I’ve been using csharpier for almost a year now and it’s amazing. Because it’s opinionated, you don’t have the space to overthink it, you just use it.
Besides, I really like its formatting style.
edtech_dev
csharpier is great. It is what "dotnet format" should be.
pjmlp
On my little enterprise bubble, the only place remaining for C and C++ is writing native libraries to be consumed by managed languages, or bindings.
The last time I wrote pure C++ applications at work, was in 2005.
Libraries still regularly.
Const-me
For the last few years, I’ve been developing CAM/CAE software on my job, sometimes embedded Linux.
Same experience: last time I developed software written entirely in C++ was in 2008. Nowadays, only using C++ for DLLs consumed by C#, for 2 reasons: manually vectorized SIMD for CPU bound numerical stuff, and consuming C or C++ libraries like GPU APIs, MS Media Foundation, or Eigen.
jiggawatts
Sometimes I feel like there ought to be a Hacker News like forum for us dinosaurs stuck in the Enterprise tarpit. Instead of talking about Elixir and AWS startup credits, we’d complain about the weather and legacy CORBA components.
pjmlp
Indeed, it could be interesting.
What do you mean by CORBA, isn't that the cool new shiny WebAssembly components? :)
radicalbyte
I've been using it since 2002 so you can imagine my opinion when jumping to other languages. They've been very good to steal all of the things that worked from other languages and constantly iterate on their core infrastructure and language.
atombender
Do you know about any sizeable open source projects written in C#, other than what Microsoft has produced? I rarely come across anything written in it.
Alupis
It's a curious thing, the .NET ecosystem. The overwhelming majority of it's ecosystem seems to be dominated by Microsoft first-party libraries and frameworks. 3rd party libraries and frameworks seem to either get swallowed up by Microsoft, killed, or never reach critical-mass.
Often in the .NET ecosystem, it seems there is exactly one library or framework for thing $X or $Y. Whereas in the JVM ecosystem, you have 30+ logging libraries, 87 different MVC frameworks, etc. (yes, I'm being a bit facetious, but you get the point).
I imagine .NET developers often think this is a good thing, in regard to their ecosystem. No guessing what to use, just go with the "blessed" path and don't think about it. And, to that end, there is some obvious merit to this.
However, I feel the .NET ecosystem loses out on cross-pollination of ideas. There's zero possibility Microsoft's employees just happen to make the best frameworks and libraries... there should be many web frameworks - each competing for mindshare and trying to out-innovate each other, each with their own pro's and con's, etc.
So, while .NET might be technically open source, it still feels rather like a closed source ecosystem, controlled by a single corporate entity.
cogman10
That because that's the environment MS nurtured for over a decade. They were openly hostile to things like nuget up until like 2016 or so.
They purposefully made it painful to venture out of the MS ecosystem.
legulere
There are several logging libraries for .net as well, microsoft even lists them: https://learn.microsoft.com/en-us/dotnet/core/extensions/log...
Libraries getting swallowed up is not so bad as it sounds. For instance for web frameworks there was a phase of experimentation with projects like Nancy that inspired changes for asp.net core. There is still alternatives like fast endpoints.
Also you have things happening like integrated system.text.json replacing newtonsoft.json that over time took on some cruft.
75345d4c
Why would anyone make a .NET open source library when Microsoft is quick to squash anything that is actually useful with their own open source implementation?
Microsoft still has some lessons to learn about fostering an active open source ecosystem -- of course, unless they are intentionally suppressing it in .NET.
mattmanser
It's weird you using logging as there used to be 3/4 different libraries people used (nlog, log4net, elmah, another one I forget?).
Then serilog came out and pretty much everyone switched to that in a very short period.
jamesfinlayson
https://github.com/paintdotnet was the first one that came to mind.
zigzag312
https://github.com/MonoGame/MonoGame (runs even on consoles, which is rare for open source game frameworks and engines)
https://github.com/SubtitleEdit/subtitleedit
https://github.com/jellyfin/jellyfin
https://github.com/AvaloniaUI/Avalonia
https://github.com/bitwarden/server
https://github.com/unoplatform/uno
https://github.com/files-community/Files
https://github.com/NickeManarin/ScreenToGif
https://github.com/DevToys-app/DevToys
https://github.com/d2phap/ImageGlass
https://github.com/ShareX/ShareX
https://github.com/duplicati/duplicati
https://github.com/OpenRA/OpenRA
https://en.wikipedia.org/wiki/Ryujinx
https://sourceforge.net/projects/keepass/
jayd16
The FFXIV extension/mod tool is a fun example.
tracker1
Can't speak for FLOSS, but I've worked on massive projects in various Banking, Govt and eLearning spaces. I've never really hurt for library support via NuGet either. It's honestly not always my first choice, but pays the bills.
I mostly just dislike a lot of the excessive use of "Enterprise Patterns" for projects that don't come close to actually needing them.
louthy
Not sure what your definition of sizable is. But if it’s just physical size of repo then my language-ext project [1] is about half a million lines of code, ~7,000 stars, and ~25 million downloads.
We are out there :)
369548684892826
Jellyfin / Emby
A lot of the *arr tools like Sonarr
Bitwarden and Keepass
majora2007
Kavita (self hosting for books/comics)
orphea
Ryujinx, a state-of-the-art Switch 1 emulator, was open source and written in C#
Nelkins
Akka.NET and AvaloniaUI are two big ones.
edtech_dev
I'll add Orchard CMS to this list. Also a lot of the seven seas software.
null
radicalriddler
I despise working with Nuget. Whether it's a restore, managing your csproj, or publishing packages, compared to NPM it's an absolute mess.
Ygg2
> .NET was the most sane programming ecosystem that I worked in.
Having written libraries in .Net I fully disagree with that notion.
First insanity is figuring out what in the fuck you need to support. .Net framework or .Net standard or .Net Core or Mono (or .Net Duplo or .Net dot nes :P).
Second is the Source generators. I swear using t4 templates is the saner option. I've had cached artifacts appearing out of the fucking nowhere like unkillable zombies despite closing the Rider, clearing its cache, and killing build server.
Third is the availability of packages. In Rust and Java there are like several libs for anything (even if C bindings).
wvenable
> First insanity is figuring out what in the fuck you need to support.
Since I no longer support .NET Framework, it's just .NET now.
.NET was two platforms for a while and they did a lot of weird stuff to make that work (.NET standard) but it's been one platform for many versions now so that specific difficulty can mostly be ignored.
Ygg2
Easy to say, but it poiets to ecosystem fracture. But I've been getting requests to support really weird and outlandish versions. Stuff like Mono and .Net 4.56
meibo
Most C# libraries I use are outdated, crappy and do just a little less than what I need. Also, most Rust libraries I try to use are outdated, crappy and do just a little less than what I need. Maybe what I need is niche but my experience is pretty similar in that regard.
null
mattgreenrocks
All I want is for dotnet watch to behave in a predictable way. In .NET 9, even when using —no-hot-reload, sometimes CSS changes to components are not picked up on Blazor components.
It’s so aggravating because ASP.NET with server side Blazor components really has it all: type safety, server-side components ala Astro, fantastic ORM model, great runtime perf. But this little issue makes dev quite tedious at present: did I mistype a Tailwind class name, or did dotnet watch miss the change?
rafaelmn
I inherited an MVC app that has a bunch of jQuery rendering crap and I would like to move to server side components - since you seem to be into Blazor Server side - have you heard of HTMX ?
What would you say would be the benefit of Blazor vs HTMX and Razor Pages for subviews ?
My experience with Microsoft UI toolkits after winforms, is that they are all janky over-engineered stuff (Silverlight/WPF/Xamarin/Maui) terrible tooling and support compared to alternatives. And Blazor using websockets makes me believe it is the same. The compile to WASM idea is a typical example of this.
So what would be the selling point of Blazor ? It feels like you are just bundling stuff into Blazor magic when you could KISS with something simple like HTMX ?
WorldMaker
I still haven't found a use-case for the websocket Blazor Hybrid and it still smells so much like the worst mistakes of the original ASP (before .NET) and the `runat="client"` versus `runat="server"` confusions.
Blazor WASM makes some sense if Silverlight ever made sense for a project: it's a way to ship C# directly to the browser for maximal code sharing with other C# projects in a C# ecosystem. It's basically "what if Angular/React was just Razor Pages running on the browser?"
It's absolutely the opposite of KISS, it's lifting and shifting the entire .NET runtime in WASM to the client. Outside of corporate networks and packaged apps like Electron or Tauri, I'm not sure it makes any sense. But if you like writing Razor Pages and wished they ran closer to the client metal, and you can afford the bandwidth of an entire .NET application soup-to-nuts as your SPA framework, there is a sense to it.
If all you think you need is Razor Pages with HTMX that's probably all you need.
rafaelmn
>I still haven't found a use-case for the websocket Blazor Hybrid and it still smells so much like the worst mistakes of the original ASP (before .NET) and the `runat="client"` versus `runat="server"` confusions.
That is exactly my read of it, especially given Microsoft track record on delivering with stuff like this.
Not sure about the Silverlight comparison - in the days of Flash, browsers did not even have a way to stream video reliably, nowadays it just cramming a square peg in to a round hole - heavyweight runtime built on multithreading crammed to a single threaded event loop. I have not tried it - but after using .net in much more powerful/native envs like Android - I know for a fact that the iteration/build/debugging story sucks compared to native JS/TS. Also as bad JS is, TS makes it saner, tooling has matured and DOM APIs are built for JS.
doomroot13
As of today (and going forward), there are two different flavors of Blazor server-side rendering. There is the original version where the component is rendered on the server and interactivity is provided via websockets. Now there is also static server-side rendering, which works very similarly to razor pages, pages/components are rendered on the server and there is no interactivity. You can then, of course, add interactivity wherever you'd need it with server-interactive or webassembly interactive sub-components.
I wouldn't necessarily say there's any benefit of Blazor over HTMX, it just depends on what you're most comfortable with and what works for you in your project. But you could architect your front-end in a similar way where you have small blazor components in your pages with interactivity.
I think Blazor is in a nice state now, where I can iterate very quickly on projects with just static server side rendering and add interactivity whenever it's needed. It gives me a very fast website, rendered on the server, and the option to add some interactivity whenever I need.
terandle
Blazor static server side + HTMX is probably the only way to make a cost efficient and performant version of Blazor suitable for public websites. WASM is way too big and slow, Websockets take up server resources and cause problems with timeouts where the user has to refresh their screen losing all state.
rafaelmn
What would be the benefit over Razor pages tho ? Component model ? Feels like partial views and razor templates might not be the cleanest/dry-est solution but would make the implementation super straightforawd.
tracker1
Jetbrains built some awesome tooling to support HTMX apps using razor engine and some MVC conventions. It's pretty neat.
edtech_dev
I hear a lot of complaints about dotnet watch, but my experience doesn't match. I just use it from the terminal (instead of running it from an IDE) and it mostly just works.
bob1029
> It’s so aggravating because ASP.NET with server side Blazor components really has it all
Agreed. I bailed on Blazor over the tooling experience. Editing components in VS2022 was so janky for me. Syntax highlighting and intellisense never worked correctly.
MortyWaves
I don’t think there’s ever been any good tooling for the entire collection of ASP.NET DSLs. Be that MVC, Razor, or Blazor. Genuinely the same problems I had in VS2010 still happen in VS2022.
There’s been some changes and improvements, but I really have to ask what the editor tooling team within that team are doing.
I know there are some very difficult problems involved in parsing and formatting and highlighting bastardised mixtures of HTML, C#, and JavaScript all in the same file but if anything I think that perhaps suggests it was a bad idea to begin with.
Consider the tooling for desktop and mobile apps with XAML (WPF, Avalonia) or even WinForms - they all have code behind support.
Meaning there is no need (or ability) to mix all three in the same file.
jabart
We have had great success with Maui Blazor Hybrid. Each release hot reload gets better with fewer edge cases. I also found that having a separate .cs file instead of in one file helps with highlighing and intellisense.
shortrounddev2
Are you using Visual Studio or another tool (vscode, vim, rider)? I found hot reload works a lot better in Visual Studio than any other IDE
deburo
That's true, but even in Visual Studio, Hot Reload breaks too often to be comfortable. It seems the intermediate .g.cs handling is a bit error prone.
mattgreenrocks
Rider, but I'm on Mac, so I can't use the real VS. I run dotnet watch from a terminal separately.
whoknowsidont
[flagged]
zbentley
Say more?
whoknowsidont
Why does his statement not require more substance? Why do I have to provide it? The burden is the other way around.
Blazor's architectural model makes it impossible to be "performant." It's not even debatable.
What you gain in DevEx you lose substantially in user experience.
PathOfEclipse
.NET perf can be great in the sense that it provides more tools to write C-like code while still taking advantage of safe memory management, as compared to Java. On the downside, both their JIT and their GC seem to be far less sophisticated than the JVM.
Why, for instance, does the CLR GC not have something like TLABs? The result is that it seems like .NET devs have to worry a lot more about the expense of small, short-lived allocations, while in Java these things are much cheaper.
Overall, I think it's easier to program idiomatically in Java and get decent performance out-of-the-box, while C# may provide more opportunities for optimization without having to rely on something equivalent to sun.misc.Unsafe and offheap allocations.
tekdude
Might be worth viewing the full list of changes in the blog post that the article links to:
Metalnem
Also, if you want to see the full list of changes in .NET 10 (not just the latest preview), you can find it here:
https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotn...
smackeyacky
All these changes, yet still no satisfactory UI framework.
Still no migration path from WinForms to something modern.
I love .NET but if you're taking on an older desktop app that is still using VB.NET and WinForms it feels like Microsoft have decided to let you circle the drain with no supported way forward into MAUI or whatever stupid XAML UI they decided is the solution these days.
On a server, .NET is fantastic and it's entirely possible to build and debug your system on Linux with no loss of productivity, but the desktop stuff is bad and getting worse.
cheschire
I've tried each iteration of UI paradigm they've tried since WinRT and never really had any significant problems with any of them. WinRT, UWP, WinUI, MAUI...
But then they aren't even willing to invest the time to dogfood their own products and fully replace the windows UI. Really doesn't inspire confidence.
I suspect they also made a bad bet by going so hard on blazor without putting more support behind WASM itself. Now that's stalled out with WASM's own failure to reach critical mass.
brokencode
Microsoft has zero vision in the UI space. It’s crazy that there isn’t there a single, obvious solution for developing Windows applications in 2025.
I agree that it seems they’ve made some bad bets and now are bogged down supporting half a dozen different frameworks with different limitations and tradeoffs.
They keep trying to reinvent the wheel, but it doesn’t seem like they’ve ever really meaningfully improved on WPF.
At least there is Avalonia for an open source, cross platform WPF alternative. It seems like the sanest way of making desktop applications with C# currently.
giancarlostoro
Only thing I want to hear about lately is the next major version of Visual Studio, I feel like it will never come. I always feel like every major version has drastic improvements, and I'm starved for them.
qingcharles
This thing has barely changed in the ~30 years I've been using it. There's definitely room for some more improvements.
sumtechguy
You can divide visual studio into 4 era's. The vs6 (we smashed all of our dev tooling together and its integrated decently) era, the vs2002/vs2003/vs2005 (we broke it all and you will like it and never speak of C++ again), vs2010 era (we fixed all of that from 2002 sorry about that), vs2017/vs2022 (it updates from the internet and takes forever to install and now does everything).
The problem is MS is unwilling to stick with anything dev wise. The whole ecos system is a littered realm of half forgotten techs that may or may not be supported anymore. Wrapped with very confusing messaging to the devs what to use.
tracker1
I prefer VS Code... though MS has for better or worse kept the .Net tooling relatively weak. I'll use Rider or VS on a few occasions... then retreat back to Code as much as I can.
For split web projects, definitely work on the web ui in VS Code.
jcotton42
VS2017 was the introduction of the modern VS installer that is way faster than the prior ones.
cheschire
I dunno, I think the big change over to roslyn in 2015 was a bit of a tectonic shift.
vyrotek
My guess is we'll know soon. Maybe at VS Live next week?
> "Stay tuned for more details later this summer about what's coming next for Visual Studio..."
https://learn.microsoft.com/en-us/visualstudio/releases/2022...
JaggerJo
Just buy a Rider license. Never looked back.
fsfod
Maybe they will use this chance to finally switch it away from the .NET Framework to the modern dotnet runtime with its many years optimizations.
edtech_dev
Have you tried Rider?
giancarlostoro
Yes, it was a bit rough originally, but they've managed to make it better, sadly some employers do not want to buy into JetBrains.
brainzap
They should fix github issues and write in-depth tutorials, instead of AI features or minimal API.
junto
I adore minimal API and when paired with Carter it’s just gorgeous.
https://github.com/CarterCommunity/Carter
My current absolute favorite is .NET Aspire. Build distributed applications with an OTEL support dashboard - up and running in minutes.
https://learn.microsoft.com/en-gb/dotnet/aspire/whats-new/do...
Only gap in Aspire is deployment (k8s) tooling which is on the way.
stronglikedan
"they" are more than one person and can do more than one thing at a time
Alifatisk
One-shot execution looks exciting, what problems does it solve? Less cluttering in the environment?
pjerem
Scripting, CLI tools ...
chusk3
It also solves a more subtle problem - when people install a tool globally they install latest _at that time_. But the world doesn't stand still, and things get updated. `dnx` always uses the latest available version by default (you can of course pin with `dnx <package>@<version>`) so that you never get out of date.
sergiotapia
I haven't used C#/.NET since .NET 4 - I remember it was great, yet heavily tied into Visual Studio, and forget about using CLI for things like most other languages. It was all GUI or nothing. Insurmountable XML files.
How are things these days with .NET 10! Jesus, 10!
Dudes who use it daily, what is your favorite feature you think?
WorldMaker
Favorite recent language feature is a big investment in C# pattern matching. It's a big feature from the functional programming world rare to see in "Enterprise" languages.
Favorite recent runtime feature is all the cool low level stuff opened up by Span<T> (and Memory<T>). It has a similarity to Rust borrowing, but well integrated into the CLR's existing type system. It has opened all sorts of performance code possibilities that is still memory-safe/type-safe with fewer needs for falling back to "unsafe" operations. This is not just exciting because it is an interesting playground if you like low-level programming, but also because it has been a performance flood lifting all boats in the .NET ecosystem. A lot of code over the last few years has gotten easy performance boosts by just recompiling (because the compilers were taught to prefer Span/Memory overloads when they get added; no change to C# or F# code, just the compiler picking a new performance path).
debugnik
Definitely change for F# code, some of those Span overloads broke type inference. Also, certain APIs even removed their non-Span overloads between .NET versions, which was a straight up breaking change for every language other than C#.
qingcharles
The biggest change for me has been the ability to deploy my web sites to a Linux box instead of having to deal with IIS.
WinForms app development hasn't changed one bit in 25 years.
If you code in C# then they've added some nice new language features every year to make your code a little tidier.
And the whole framework is totally open source now, which is a bonus.
There's nothing I'm really asking for. It does pretty much everything I need these days.
majora2007
Very different. That was the .NET I knew in college, .NET Core really changed the game. I personally use CLI just for EF Core (ORM) but Rider support is there so you're not tied to VS.
My fav feature is honestly how little boilerplate I need compared to Spring Boot and the syntax sugar is honestly really nice.
cyphax
My favorite feature, especially considering the past of "heavily tied into Visual Studio" is the platform independent nature of (most of) "modern" dotnet. That is to say, I run Fedora on my laptop, and I do not want Windows, yet I don't feel like a second class citizen and dotnet runs well and is available from repositories that Microsoft provides for various Linux distributions (it just hit me how strange this is, for _Microsoft_ to offer official repositories for Linux operating systems...).
I also really like that its development is fairly open (it's on github). From a more technical point of view, I think C# is a slightly better Java. A pretty nice language overall. It's not gui-or-nothing with dotnet core so it's not too difficult to create workflows for ci/cd pipelines, although the .net framework solutions we still have aren't too much harder to script: msbuild is pretty capable.
osigurdson
The version numbers used to increase much more slowly. Since the .NET (modernized / cross platform) core "track" the version number increments every year.
WorldMaker
The version increments roughly every 6 months. It's almost the exact same update cadence as NodeJS: LTS versions are even numbers released in the Fall and STS versions are odd numbers released in the Spring. STS often focuses on "bleeding edge features" and LTS often on performance and stability. (Though both are year round projects and there are bleeding edge features in an LTS and perf/stability fixes in an STS.)
rawling
https://learn.microsoft.com/en-us/lifecycle/products/microso...
The last 5 version have been released a year apart, in Novembers.
oneplane
It's still stuck in weird formats and monoliths. A lot of GUI-only stuff has been ported to the mega CLI, but it's still the weird Visual Studio format plus XML files that you cannot replace with a simple Makefile. You still can't just compile a bit of C# as-is, it must have the Solution, Project, Assembly etc. chain, the run-as-script feature is nice (lots of cheers when that was presented! even on the live stream), but it's specifically not designed to allow you to assemble a toolchain that works for what you need. There is only one and it has everything, no options.
The question, of course, becomes: when does that matter? For a lot of people who are in to .NET, they see that as a benefit. Look at Go through this lens, and it's similar; the go CLI is the compiler, linker, package manager etc. I suppose the biggest difference is that it doesn't prescribe solutions and projects and file formats to go with them, which enables you to put this in any existing CI, make or other system.
WorldMaker
> it's still the weird Visual Studio format
.NET 9 (and VS2022) added support for the SLNX replacement format to replace the old weird solution format:
https://devblogs.microsoft.com/visualstudio/new-simpler-solu...
oneplane
Yep, but you still can't say "compile and link everything in this tree". Technically, the language can, but the framework assumes specific compiler, linker and layouts on the filesystem so at that point you can't. It really wants that editor-related stuff to be part of the framework, and everything else has to bend for it.
3836293648
.NET 4 doesn't exist and was avoided on purpose. There was a .NET Framework 4, but after Framework was abandonned in favour of Core they dropped the core suffix and skipped to 5.
debugnik
> NET 10! Jesus, 10!
Well, spiritually this is the 13th(?) major version of .NET (possibly more if we count Silverlight's runtime). You missed the part when there was .NET Core 1-3 alongside the old .NET Framework 4.8., and then they skipped Core 4 and stopped supporting Framework so they could finally fix their naming scheme.
croes
I prefer .Net Framework 4.8 Longer lifetime than any .Net version.
Merad
I've upgraded apps from every version since .Net Core 2.0. The upgrades always take a few hours, maybe half a day (with the exception of 2.0 to 3.0 which took a few days - many breaking changes). It's well worth a few hours per year to get the advantages of newer languages features, enhancements in Asp.Net Core, security and performance enhancements in the .Net Runtime, etc.
brokencode
Is upgrading every 3 years really that bad? As far as I know, they typically aren’t removing features or causing disruptive changes in .NET versions.
They did when switching away from .NET Framework, but this was because they had to reimplement many features from scratch to work on other platforms, and certain parts got left behind.
ewoodrich
The last few .NET updates have been pretty much effortless updates for us. These are internal web apps and not using really esoteric C# features but that probably describes a reasonably large percentage of enterprise .NET adoption.
nartho
I don't think they introduced any breaking changes after .NET 6
nic547
.NET LTS is on a 2-year cycle, isn't it?
I've worked in .NET shops with very niche WPF/WinForms applications where customers were years behind with our software/major .NET Framework releases.
I don't think it's a technical challenge, more a cultural one.
WorldMaker
A shift in those cultural dynamics is that you can ship the current .NET LTS with your app (or even STS if you feel like making that sort of security support SLA with your own clients). You aren't relying on their Windows Update habits (or lack of them) or having to install a big .NET installer that might break their other apps.
They may still get left behind on an older version of your software because they want to be, but their relationship to Windows is no longer the big excuse/reason to skip updating to your latest that it used to be.
brokencode
You are right that it’s on a 2 year cycle. Though there is support for 3 years, so you could safely put off an upgrade for up to a year if there are breaking changes one release.
starik36
When I need to send someone an app, I usually use .NET Framework 4.8 because I know it's already installed on every recent version of Windows. This way all I have to distribute is a single very small exe. No need to package a framework with it.
Similar feat with .NET core usually results in a 70-80MB executable.
SirMaster
Is 70-80MB really a big deal to distribute in 2025?
Also if you use trim unused code and compress the executable in my experience it's usually a lot smaller than this.
croes
With all the dependencies that maybe getting an update to the new .Net version, yes.
HumanOstrich
Yea that's why I write all my programs in C using the win32 APIs. It has a lifetime even longer than .NET Framework 4.8.1! I'll never have to change or adapt to new things. /s
croes
I change things if it’s necessary, not for the sake of using the newest version.
Now I have to update software and all its dependencies without a real benefit.
It’s equivalent of buying a new PC because MS tries to force Windows 11.
Lets waste lots of time and resources for nothing.
edtech_dev
Just the amount of perf improvements they have added since .NET 4.8, year after year, is staggering.
cheschire
Having written .NET 5+ apps, and now being back to maintaining a 4.8 app...
There's a lot of quality of life features of the later versions of C# that we're missing out on. My code was a LOT more streamlined in my .NET 9 app.
devwastaken
reminder the .net compiler is IP of microsoft and they state this clearly when you invoke it on any platform other than windows. you are merging your company with microsoft and windows if you use it.
dimaaan
MIT license: https://github.com/dotnet/roslyn
jcotton42
> you are merging your company with microsoft and windows if you use it
That's not how that works. Nothing about the .NET license entitles Microsoft to what you make with the tooling.
zaphar
It is fully open source so... who cares?
My favorite .NET 10 feature so far is not within the .NET library itself, but `dotnet tool exec` to run C# files as scripts without a build step. This has been available in F# for a long time via `dotnet fsi`, and for C# also via the third party cs-script tool. It took a surprisingly long time to officially reach the primary .NET language!
I only really wish C# would’ve been directly integrated as an alternative scripting language in PowerShell. You may balk at the idea for causing a ton of cruft for people who don’t need it; ”a whole new scripting language!” But the thing is — PowerShell already builds upon .NET so supporting a new language is a rather small effort (relatively speaking) if it happens to be a .NET language. And C# just feels so much better for me to code in when the scripts grow in size. I’m not sure I’ll ever become friends with the implicit returns. C# has become particularly suitable for scripting with the recent developments in the language: https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals...