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. It is built on the Common Language Runtime (CLR), allowing programmers to write ASP code using any supported .NET language. The SOAP extension framework allows it’s components to process SOAP messages.

ASP.NET’s successor is Core. It is a re-implementation 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. MVC, Web API, and Web Pages (a platform using only Razor pages) have merged into a unified MVC 6.

ASP supports many different development models:

  • Classic ASP
  • Web Forms
  • MVC
  • Web Pages
  • API
  • Core


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

ASP.NET Web Pages

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


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


  • API is an API application model (Application Programming Interface).
  • Is being merged into the new core.

ASP.NET Web Forms

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