ASP.NET Core 10: Easy support of local multi host

This article explains how ASP.NET Core 10 introduces first-class support for the .localhost top-level domain, making it easy to run multiple hostnames (e.g., api.localhost, admin.localhost) locally without editing the hosts file or using mkcert. It covers the technical background (RFC 2606/6761), Kestrel's recognition of .localhost as loopback, and updated HTTPS dev certificates. Three configuration methods are detailed: UseUrls in Program.cs, Kestrel endpoints in appsettings.Development.json, and launch profiles in launchSettings.json. The article is a technical guide for .NET developers working on multi-service architectures.