It is a Web application framework developed by Microsoft. It  allows  programmers to build dynamic Web sites, Web applications and Web services. was released in January 2002 with version 1.0 of the .NET Framework for the first time. It is the successor to Active Server Pages (ASP) technology of Microsoft.  ASP.NET is built on the CLR-  Common Language Runtime, allowing programmers to write ASP.NET programs using any supported .NET language.