.NET Core and Mono open source frameworks, and available IDEs.
.NET Core Only
Visual Studio Code (aka VS Code) is plugin-based IDE that by itself won’t just run C#. You have to install the C# plugin, and NuGet Package Manager.
.NET Core and Mono
You can use the aCute plugin on top of the established and popular Eclipse IDE. This C# extension for Eclipse IDE relies on OmniSharp and Language Server Protocol. It comes with complete edition features for C# in the Eclipse IDE, relying on the Eclipse IDE provides all typical features of a good IDE (Polyglot development, SCM, deployment…) and give access to a rich ecosystem of extensions for about all existing technologies.
$ sudo dnf install eclipse eclipse-mpc
then install the aCute extension from Eclipse Marketplace
MonoDevelop provides the best C# experience on Mono, the open-source multiplatform implementation of the .NET Framework.
$ sudo dnf install monodevelop
What would we recommend? VS Code is great for .NET Core and MonoDevelop for Mono. C# in Eclipse IDE is still young and not very friendly to former Windows developer, but it can be useful if you’re already an Eclipse IDE user.