The following list shows the most common technologies not directly found in ASP.NET Core and .NET Core, though some can be used via multi-targeting features:

• ASP.NET Web Forms applications: The legacy Web Forms technology is only available using the full classic .NET Framework; you cannot use ASP.NET Core and .NET Core for these types of applications.
• ASP.NET Web Pages applications: They are not included in ASP.NET Core 3 as such, but it is possible to use the Razor web pages engine to provide the same functionalities.
• WCF Services: ASP.NET Core 3 contains a WCF client for accessing WCF services, but creating WCF services is not supported.

Not all of the templates available for ASP.NET Core 3 support all of the major .NET languages; for example, the only template available for VB.NET is GtkSharp, with F# having a few more templates, including the ASP.NET Core web API and F# TypeProvider templates. A more comprehensive list of what templates are available for what language can be found at this link: https://github.com/dotnet/templating/wiki/Available-templates-for-dotnet-new.