ASP.NET (software)
Initial releaseJanuary 5, 2002; 22 years ago (2002-01-05)
Stable release
4.8.1 / August 9, 2022; 23 months ago (2022-08-09)[1]
Written in.NET languages
Operating systemMicrosoft Windows, Linux, macOS
Platform.NET Framework
TypeWeb framework
LicenseProprietary software[2] Edit this on Wikidata
ASP.NET (file format)
Filename extension.aspx, .cshtml, .vbhtml
Internet media type
Developed byMicrosoft

ASP.NET is a 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, applications and services. The name stands for Active Server Pages Network Enabled Technologies.

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.

In 2016, Microsoft released ASP.NET Core as ASP.NET's successor. This new version 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 (codename "Roslyn") 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.[3]

Programming models

ASP.NET supports a number of programming models for building web applications:[4]

Other ASP.NET extensions include:

IIS integrated pipeline

On IIS 6.0 and lower, pages written using different versions of the ASP framework cannot share session state without the use of third-party libraries. This does not apply to ASP.NET and ASP applications running side by side on IIS 7. With IIS 7.0, modules may be run in an integrated pipeline that allows modules written in any language to be executed for any request.[7]

Third-party frameworks

It is not essential to use the standard Web forms development model when developing with ASP.NET. Noteworthy frameworks designed for the platform include:


ASP.NET's release history tightly correlates with the .NET Framework releases:

Date Version Remarks New ASP.NET related features
January 16, 2002 Old version, no longer maintained: 1.0 First version

released together with Visual Studio .NET

  • Object-oriented Web application development supporting inheritance, polymorphism and other standard OOP features
    • Developers are no longer forced to use Server.CreateObject(...), so early-binding and type safety are possible.
  • Based on Windows programming; the developer can make use of DLL class libraries and other features of the Web server to build more robust applications that do more than simply rendering HTML (e.g., exception handling)
April 24, 2003 Old version, no longer maintained: 1.1 released together with Windows Server 2003

released together with Visual Studio .NET 2003

  • Mobile controls
  • Automatic input validation
November 7, 2005 Old version, no longer maintained: 2.0

codename Whidbey
released together with Visual Studio 2005 and Visual Web Developer Express
and SQL Server 2005

  • New data controls (GridView, FormView, DetailsView)
  • New technique for declarative data access (SqlDataSource, ObjectDataSource, XmlDataSource controls)
  • Navigation controls
  • Master pages
  • Login controls
  • Themes
  • Skins
  • Web parts
  • Personalization services
  • Full pre-compilation
  • New localization technique
  • Support for 64-bit processors
  • Provider class model
November 21, 2006 Old version, no longer maintained: 3.0 Released with Windows Vista
November 19, 2007 Old version, no longer maintained: 3.5 Released with Visual Studio 2008 and Windows Server 2008
  • New data controls (ListView, DataPager)
  • ASP.NET AJAX included as part of the framework
  • Support for HTTP pipelining and syndication feeds.
  • WCF support for RSS, JSON, POX and Partial Trust
  • All the .NET Framework 3.5 changes, like LINQ etc.
August 11, 2008 Old version, no longer maintained: 3.5 Service Pack 1 Released with Visual Studio 2008 Service Pack 1
  • Incorporation of ASP.NET Dynamic Data
  • Support for controlling browser history in an ASP.NET AJAX application
  • Ability to combine multiple JavaScript files into one file for more efficient downloading
  • New namespaces System.Web.Abstractions and System.Web.Routing
April 12, 2010 Old version, no longer maintained: 4.0 Released with Visual Studio 2010

Parallel extensions and other .NET Framework 4 features

The two new properties added in the Page class are MetaKeyword and MetaDescription.

August 15, 2012 Old version, no longer maintained: 4.5 Released with Visual Studio 2012 and Windows Server 2012 for Windows 8

Parallel extensions and other .NET Framework 4.5 features

October 17, 2013 Old version, no longer maintained: 4.5.1 Released with Visual Studio 2013[8] for Windows Server 2012 R2 and Windows 8.1
May 5, 2014[9] Older version, yet still maintained: 4.5.2
  • Higher reliability HTTP header inspection and modification methods
  • New way to schedule background asynchronous worker tasks
July 20, 2015[9] Older version, yet still maintained: 4.6 Released[10] with Visual Studio 2015[11] and EF 7 Previews for Windows Server 2016 and Windows 10
  • HTTP/2 support when running on Windows 10
  • More async task-returning APIs
November 30, 2015[9] Older version, yet still maintained: 4.6.1
August 2, 2016[9] Older version, yet still maintained: 4.6.2
  • Improved async support (output-cache and session providers)
April 11, 2017[9] Older version, yet still maintained: 4.7 Included in the Windows 10 Creators Update[12]
  • operating system support for TLS protocols
October 17, 2017[9] Older version, yet still maintained: 4.7.1 Included in the Windows 10 Fall Creators Update.[13]
  • Improved accessibility
  • Value tuple types serialization
  • SHA-2 support
April 30, 2018[9] Older version, yet still maintained: 4.7.2
August 09, 2022[9] Current stable version: 4.8.1 Released[14]
  • JIT and NGEN Improvements
  • Updated ZLib
  • Reducing FIPS Impact on Cryptography
  • Accessibility Enhancements for WinForms
  • Service Behavior Enhancements for WCF
  • High DPI Enhancements, UIAutomation Improvements for WPF
November 18, 2015 Old version, no longer maintained: 5 RC1 This version was later separated from ASP.NET and brought into a new project called ASP.NET Core, whose versioning started at 1.0.[15] An entirely new project with different development tenets and goals
Old version
Older version, still maintained
Latest version
Latest preview version
Future release

Other implementations

The Mono Project supports "everything in .NET 4.7 except WPF, WWF, and with limited WCF and limited ASP.NET 4.7 async stack."[16] ASP.NET can be run with Mono using one of three options: Apache hosting using the mod_mono module, FastCGI hosting, and XSP.

See also



  1. ^ ".net framework download page".
  2. ^ "Microsoft .NET Framework Redistributable EULA". MSDN. Microsoft. Archived from the original on April 2, 2015. Retrieved February 28, 2015.
  3. ^ "Introduction to ASP.NET 5 — ASP.NET 0.0.1 documentation". Archived from the original on May 8, 2020. Retrieved May 11, 2020.
  4. ^ "Choose between ASP.NET and ASP.NET Core".
  5. ^ "ASP.NET Web Pages (Razor) FAQ".
  6. ^ "Get Started with ASP.NET Web API 2 (C#)".
  7. ^ "How to Take Advantage of the IIS 7.0 Integrated Pipeline".
  8. ^ "Announcing release of ASP.NET and Web Tools for Visual Studio 2013".
  9. ^ a b c d e f g h ".net framework product lifecycle".
  10. ^ "Announcing .NET Framework 4.6".
  11. ^ "Visual Studio 2015 and Visual Studio 2013 Update 5 Released". Microsoft.
  12. ^ "Announcing the .NET Framework 4.7". 5 April 2017.
  13. ^ "Announcing the .NET Framework 4.7.1". 17 October 2017.
  14. ^ "Announcing the .NET Framework 4.8". 18 April 2019.
  15. ^ "Releases". GitHub.
  16. ^ "Compatibility | Mono". Compatibility | Mono. 8 September 2015. Archived from the original on 2 July 2016. Retrieved 29 August 2016.

General sources