Introduction and basic information about Microsoft ASP.NET


ASP.NET is a modern Microsoft's server side scripting technology that enables scripts (embedded in web pages) to be executed by an Internet server. ASP stands for Active Server Pages.

ASP.NET is a program that runs inside IIS (Internet Information Services). IIS is Microsoft's web server (like Apache on Linux platform). IIS comes as a free component with all Windows Server editions.


Wh​at is ASP?

Microsoft's previous server side scripting technology ASP (Active Server Pages) is now often called classic ASP, with version 3.0 being the last version of classic ASP. Scripts created by this old technology have an .asp file extension and ASP.NET main program files use .aspx file extension.

ASP.NET is the next generation of Active Server Pages, but it's not an upgraded version of ASP. ASP.NET is an entirely new technology for server-side scripting. It was written from the ground up and is not backward compatible with classic ASP.

ASP.NET features

Better language support

ASP.NET uses ADO.NET and supports full Visual Basic, not just VBScript and also supports C# (C sharp), C++ and JScript and many other programming languages.

ASP.NET programmable controls

ASP.NET contains a large set of HTML controls. Almost all HTML elements on a page can be defined as ASP.NET control objects that can be controlled by scripts. ASP.NET also contains a new set of object-oriented input controls, like programmable list-boxes and validation controls. A new data grid control supports sorting, data paging, and everything you can expect from a dataset control.

Event aware controls, event-driven programming

All ASP.NET objects on a Web page can expose events that can be processed by ASP.NET code. Load, Click and Change events handled by code makes coding much simpler and much better organized.

ASP.NET components

ASP.NET components are heavily based on XML. Like the new AD Rotator, that uses XML to store advertisement information and configuration.

User authentication

ASP.NET supports form-based user authentication, cookie management, and automatic redirecting of unauthorized logins.

User accounts and roles

ASP.NET allows user accounts and roles, to give each user (with a given role) access to different server code and executables.

High scalability

Much has been done with ASP.NET to provide greater scalability. Server-to-server communication has been greatly enhanced, making it possible to scale an application over several servers. One example of this is the ability to run XML parsers, XSL transformations and even resource hungry session objects on other servers.

Increased performance, compiled code

The first request for an ASP.NET page on the server will compile the ASP.NET code and keep a cached copy in memory. ASP.NET supports also whole caching system. The result of this is greatly increased performance.

Easy Configuration

Configuration of ASP.NET is done with plain text files. Configuration files can be uploaded or changed while the application is running. No need to restart the server. No more metabase or registry puzzle.

Easy Deployment

No more server-restart to deploy or replace compiled code. ASP.NET simply redirects all new requests to the new code.


ASP.NET is not fully compatible with earlier versions of ASP, so most of the old ASP code will need some changes to run under ASP.NET. To overcome this problem, ASP.NET uses a new file extension ".aspx". This will make ASP.NET applications able to run side by side with standard ASP applications on the same server.

What is an ASP.NET file?

An ASP.NET file is just the same text file as an HTML file, but ASP.NET file can contain HTML, XML, and scripts. Scripts in an ASP.NET file are executed on the server. ASP.NET file has the file extension .aspx.

How does ASP.NET work?

When a browser requests an HTML file, the server returns the file. When a browser requests an ASP.NET file, IIS passes the request to the ASP.NET engine on the server. The ASP.NET engine reads the file, line by line, and executes the scripts in the file. Finally, the ASP.NET file is returned to the browser as plain HTML.

What is ASP+?

ASP+ is the same as ASP.NET, it is just an early name used by Microsoft when they developed ASP.NET.

What is the Microsoft .NET Framework?

The .NET Framework is the infrastructure for the Microsoft .NET platform.  The .NET Framework is an environment for building, deploying, and running Web applications and Web Services. Microsoft's first server technology ASP (Active Server Pages), was a powerful and flexible "programming language". But it was too code oriented. It was not an application framework and not an enterprise development tool. The Microsoft .NET Framework was developed to solve this problem.

.NET Frameworks keywords:

  • Easier and quicker programming
  • Reduced amount of code
  • Declarative programming model
  • Richer server control hierarchy with events
  • Larger class library
  • Better support for development tools

The .NET Framework consists of 3 main parts:

Programming languages:

  • C# (Pronounced C sharp)
  • Visual Basic (VB .NET)
  • J# (Pronounced J sharp)

Server technologies and client technologies:

  • ASP.NET (Active Server Pages)
  • Windows Forms (Windows desktop solutions)
  • Compact Framework (PDA / Mobile solutions)

Development environments:

  • Visual Studio .NET (VS .NET)
  • Visual Web Developer


ASP.NET 2.0 improves upon ASP.NET by adding support for several new features.


ASP.NET 3.0 is not a new version of ASP.NET. It's just the name for a new ASP.NET 2.0 framework library with support for Windows Presentation Foundation, Windows Communication Foundation, Windows Workflow Foundation; and Windows CardSpace.

Related software and links:

ASP.NET icon

ASP.NET    Microsoft Windows platform
A web application framework used to create dynamic web sites, web applications and web services


ASP.NET Visual Designer    Linux/Unix platform
A Visual design surface for ASP.NET


Microsoft Internet Information Services    Microsoft Windows platform
A web server application for Windows

Microsoft Visual Studio icon

Microsoft Visual Studio    Multiplatform platform
IDE for creating programs, or websites and web applications


Add new comment about “What is ASP.NET?

Related file extensions

asax - ASP.NET application optional source

aspx - Active Server Page Extended ASP.NET script

Go to:
Article related software
Add comments...

Enter any file extension without dot (e.g. pdf)
Search for file extension details and associated application(s)

RSS feed