Microsoft Blazor is in Preview status but no longer Experiment
2019 April 18, Microsoft Blazor Project leader Daniel Roth announces that Blazor is in official Preview status, it is no longer experiment.
With this newest Blazor release we're pleased to announce that Blazor is now in official preview! Blazor is no longer experimental and we are committing to ship it as a supported web UI framework including support for running client-side in the browser on WebAssembly.
(from Daniel Roth's blog)
The original blazor.net website is gone but the URL is redirected to the new Microsoft Blazor web page here
What is Blazor?
Blazor was a Microsoft experimental project which is with the goal of building a client web UI framework based on .NET and WebAssembly. Developers can use Blazor to "Build rich interactive UIs using C# instead of JavaScript.".
Blazor brings epoch-making significance to the .NET developers. Because most of .NET programmers are not comfortable with JavaScript writing webpages because they are more familiar .Net. Now, They can write web client UI using C# instead of JavaScript.
Server-side Blazor and Client-side Blazor
In the newer Blazor version, the old Server Component (or called as ASP.NET Core Razor Component) is named back to Server-side Blazor. The old client Blazor is named to Client-side Blazor.
Server-side Blazor runs on the server via SignalR
Client-side Blazor runs client-side on WebAssembly
Please read more information from Daniel Roth's blog.