CoreCLR VS winforms

Yes, that is true. I'm not sure about JVM implementation details but the reason the comment says "virtual and interface" calls is to outline the difference. Virtual calls in .NET are sufficiently close[0] to virtual calls in C++. Interface calls, however, are coded differently[1].

Also you are correct - virtual calls are not terribly expensive, but they encroach on ever limited* CPU resources like indirect jump and load predictors and, as noted in parent comments, block inlining, which is highly undesirable for small and frequently called methods, particularly when they are in a loop.

* through great effort of our industry to take back whatever performance wins each generation brings with even more abstractions that fail to improve our productivity

[0] https://github.com/dotnet/coreclr/blob/4895a06c/src/vm/amd64...

[1] https://github.com/dotnet/runtime/blob/main/docs/design/core... (mind you, the text was initially written 18 ago, wow)

Sort of, some topic are not relevant anymore, consider this - https://github.com/dotnet/coreclr/tree/master/Documentation/botr

Fairly advanced stuff but the Book Of The Runtime (BOTR) it's a invaluable resource

After that you can check out the The Book of the Runtime, which is the CoreCLR version of the previous book.

Technically the restrictions already exist, just as a part of the development experience.

- .NET Hot Reload is only implemented on Windows. It requires support in the .NET runtime, which is technically possible to implement, but the team has not gotten around to implementing it for years. This doesn't have to do with the issue around MS removing the "dotnet watch" command, it's for the "Edit and Continue" feature in IDEs.[1][2]

- MS was considering deprecating Omnisharp, the open-source language server that implements C# support for VS Code, and replacing it with a closed-source version. Since the announcement, commits to omnisharp-vscode have dropped off significantly. The lack of Omnisharp would mean there would be no real open-source C# development environment for Linux anymore, since MonoDevelop was abandoned a few years ago. [3]

[1] https://youtrack.jetbrains.com/issue/RIDER-31366/EditContinu...

[2] https://github.com/dotnet/coreclr/issues/23685

[3] https://github.com/omnisharp/omnisharp-vscode/issues/5276

The next step is to realize everything you think you know about .NET is just an abstraction. Next step is to learn about what is going on behind all that syntax sugar and facades. 1st step might be https://github.com/dotnet/coreclr/tree/master/Documentation/botr then go down the rabbit hole and have fun

Book of the Runtime

As for the books, back in the days I really enjoyed reading “CLR via C#" by Jeffrey Richter which helped a lot to understand what is under the hood. Other from that, try The Book of the Runtime

Windows Forms[0] is still alive and will never die, and very low overhead to start with, and works on new and shiny .NET 8.

If Linux or macOS, you can use AvaloniaUI[1] instead which is sufficiently advanced but assumes some prior knowledge.

[0] https://github.com/dotnet/winforms/blob/main/docs/getting-st...

[1] https://docs.avaloniaui.net/docs/get-started/

Winforms: Licencia MIT.

3. Therefore reified generics are not possible to implement in a backwards compatible way.

Ok, sure, but if you instead a new generic collection types and leave the old ones alone, you don’t have to worry about breaking existing compiled code.

This comment about C# suggests a lack of familiarity with the approach C# took:

> C# made the opposite choice — to update their VM, and invalidate their existing libraries and all the user code that dependend on it.

All of the pre-generic C# libraries continue to exist to this day (ArrayList, HashTable, and the non-generic IEnumerable). Applications that used them never stopped working. New code uses the generic collections (List and Dictionary).

Anyways, I think the costs that Java is currently paying for non-reified generics (reflection, performance, and type safety mentioned in the article) is not worth the backwards comparability with the 20 year old J2SE 1.4. The price C# pays for making a backwards incompatible generics (mostly some minor annoyance when designing a collection class implementing IEnumerable) is worth it at this point.

P.S. ok, I do admit that C# forking the collection library is still causing ongoing maintenance work 18 years later: https://github.com/dotnet/winforms/pull/8673

No, it is fully supported and in active development. https://github.com/dotnet/winforms

No, it's still under active development/maintenance. https://github.com/dotnet/winforms/graphs/contributors

The image is kept in-memory— https://github.com/dotnet/winforms/blob/main/src/System.Windows.Forms/src/System/Windows/Forms/PictureBox.cs

Appears that this has been broken for a while. Seems it has something to do with the new designers being run out of process.

Also, the runtime that C# runs on, is also completely open source as well (https://github.com/dotnet/runtime); ASP.NET which is used to create web apps in C# is open as well (https://github.com/dotnet/aspnetcore). WinForms/WPF, used to make desktop apps in C# is also open source (https://github.com/dotnet/wpf, https://github.com/dotnet/winforms). All of the source code for these are on the dotnet Github page: https://github.com/dotnet and most are all MIT-licensed.

You'll likely have to open an issue against https://github.com/dotnet/winforms. If you've already opened an issue here, then feel free to link and I might be able to provide suggestions on how to improve the triage process.