ASP.NET is an open-source server-side web application framework designed for web development to produce dynamic web pages. It was developed by Microsoft to allow programmers to build dynamic web sites, web applications and web services.
It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft’s Active Server Pages (ASP) technology. ASP.NET is built on the Common Language Runtime (CLR), allowing programmers to write ASP.NET code using any supported .NET language. The ASP.NET SOAP extension framework allows ASP.NET components to process SOAP messages.
ASP.NET’s successor is ASP.NET Core. It is a re-implementation of ASP.NET as a modular web framework, together with other frameworks like Entity Framework. The new framework uses the new open-source .NET Compiler Platform and is cross platform. ASP.NET MVC, ASP.NET Web API, and ASP.NET Web Pages (a platform using only Razor pages) have merged into a unified MVC 6.

ASP supports many different development models:

  • Classic ASP
  • ASP.NET Web Forms
  • ASP.NET Web Pages
  • ASP.NET Core


  • ASP.NET was released in 2002 as a successor to Classic ASP.
  • ASP.NET pages have the extension .aspx and are normally written in C# (C sharp).
  • ASP.NET 4.6 is the latest official version of ASP.NET.
  • ASP.NET 5 was expected to be an important redesign of ASP.NET.

ASP.NET Web Pages

  • ASP.NET Web Pages is an SPA application model (Single Page Application).
  • The SPA model is quite similar to PHP and Classic ASP.
  • ASP.NET Web Pages is being merged into the new ASP.NET Core.


  • ASP.NET MVC is an MVC application model (Model-View-Controller).
  • ASP.NET MVC is being merged into the new ASP.NET Core.


  • ASP.NET API is an API application model (Application Programming Interface).
  • ASP.NET API is being merged into the new ASP.NET Core.

ASP.NET Web Forms

  • ASP.NET Web Forms is an event driven application model.
  • ASP.NET Web Forms is not a part of the new ASP.NET Core.