New REPL on the browser for .NET !

The astonishment goodness inclusion in the release of ASP.NET Core 1.0 RTM was a browser-based REPL (Read-Eval-Print-Loop) for .NET at from which, there’s a great set of tutorials and in-browser development experience for .NET. You can now get started learning .NET without installing Visual Studio or and SDKs. Or even get started learning .NET While you wait for Visual Studio to install.

Take a moment and head over to and check out the download page. It's got a really nice place you can try out C# directly in the browser without having to install anything! There's also a great C# Tutorial with interactive browser-based tools as well.

This new way is a powerful tool to present and teach .NET concepts. Non .NET developers can use it to discover the C# language and test the .NET Framework without installing any tools and on any OS. All we need is a browser!


If you right-click inside the browser-based code editor, you will get a context menu with 2 features :

  • Change All Occurrences (Keyboard Shortcut: Ctrl+F2) : it's useful for refactoring.
  • Command Palette (Keyboard Shotcut: F1) : it's a rich command palette where commands are alphabetically sorted.

Notice here the scrolling list of commands inside the command palette:

It is easy to find a command by typing it in the command palette where you see also the shortcut to memorize it.


If you want to build muscle memory to use only the keyboard like I prefer to use, there is plenty of useful keyboard shortcuts that we could use. The list is long but I will introduce some few of them :

  • Add Cursor Above = Ctrl+Alt+UpArrow
  • Add Cursor Below = Ctrl+Alt+DownArrow
  • Add Line Comment = Ctrl+K Ctrl+C
  • Add Selection to Next Find Match = Ctrl+D
  • Change All Occurrences = Ctrl+F2 which is by default in the context menu.

What if you have a previous language experience?

Someone on facebook asked me if there is VB REPL. And here is how I answered his interesting question:


All the tutorials are customizable according to your previous language experience.
alt Until this moment of writing, there are twenty lessons on C# covering LINQ, TDD, Dates, Times, Strings, etc. So Let's try it! Enjoy it! Play with it!

Hi, I'm Maher, Development Technologies MVP. I'm blogging about ASP.NET Core and Microsoft Azure.