It is a redesign of ASP.NET that unites the previously separate ASP.NET MVC and ASP.NET Web API into a single programming model.

[3][4] Despite being a new framework, built on a new web stack, it does have a high degree of concept compatibility with ASP.NET.

ASP.NET Core initially ran on both the Windows-only .NET Framework and the cross-platform .NET.

[6] Originally deemed ASP.NET vNext, the framework was going to be called ASP.NET 5 when ready.

However, in order to avoid implying it is an update to the existing ASP.NET framework, Microsoft later changed the name to ASP.NET Core at the 1.0 release.