Developer Productivity
ASP.NET helps you deliver real world Web applications in record time.

• Easy Programming Model.  ASP.NET makes building real world Web applications dramatically easier.  ASP.NET server controls enable an HTML-like style of declarative programming that let you build great pages with far less code than with classic ASP.  Displaying data, validating user input, and uploading files are all amazingly easy.  Best of all, ASP.NET pages work in all browsers -- including Netscape, Opera, AOL, and Internet Explorer.
  
  
• Flexible Language Options .  ASP.NET lets you leverage your current programming language skills.  Unlike classic ASP, which supports only interpreted VBScript and JScript, ASP.NET now supports more than 25 .NET languages (including built-in support for VB.NET, C#, and JScript.NET -- no tool required), giving you unprecendented flexibility in your choice of language.
  

• Great Tool Support.  You can harness the full power of ASP.NET using any text editor -- even Notepad!  But Visual Studio .NET adds the productivity of Visual Basic-style development to the Web.  Now you can visually design ASP.NET Web Forms using familiar drag-drop-doubleclick techniques, and enjoy full-fledged code support including statement completion and color-coding.  VS.NET also provides integrated support for debugging and deploying ASP.NET Web applications.

The Enterprise versions of Visual Studio .NET deliver life-cycle features to help organizations plan, analyze, design, build, test, and coordinate teams that develop ASP.NET Web applications.  These include UML class modeling, database modeling (conceptual, logical, and physical models), testing tools (functional, performance and scalability), and enterprise frameworks and templates, all available within the integrated Visual Studio .NET environment.

• Rich Class Framework.  Application features that used to be hard to implement, or required a 3^rd-party component, can now be added in just a few lines of code using the .NET Framework.  The .NET Framework offers over 4500 classes that encapsulate rich functionality like XML, data access, file upload, regular expressions, image generation, performance monitoring and logging, transactions, message queuing, SMTP mail, and much more!

Improved Performance and Scalability
ASP.NET lets you use serve more users with the same hardware.

• Compiled execution.  ASP.NET is much faster than classic ASP, while preserving the "just hit save" update model of ASP.  However, no explicit compile step is required!  ASP.NET will automatically detect any changes, dynamically compile the files if needed, and store the compiled results to reuse for subsequent requests.  Dynamic compilation ensures that your application is always up to date, and compiled execution makes it fast.  Most applications migrated from classic ASP see a 3x to 5x increase in pages served.
  
  
• Rich output caching. ASP.NET output caching can dramatically improve the performance and scalability of your application.  When output caching is enabled on a page, ASP.NET executes the page just once, and saves the result in memory in addition to sending it to the user.  When another user requests the same page, ASP.NET serves the cached result from memory without re-executing the page.   Output caching is configurable, and can be used to cache individual regions or an entire page.  Output caching can dramatically improve the performance of data-driven pages by eliminating the need to query the database on every request.
  
  
• Web-Farm Session State. ASP.NET session state lets you share session data user-specific state values across all machines in your Web farm.  Now a user can hit different servers in the web farm over multiple requests and still have full access to her session.  And since business components created with the .NET Framework are free-threaded, you no longer need to worry about thread affinity.
  
  
• Microsoft .NET Outperforms J2EE.  In a head-to-head comparison of performance and scalability between Sun's Java Pet Store J2EE blueprint application and the ASP.NET implementation, Microsoft .NET significantly outperformed J2EE.  The bottom line: the ASP.NET implementation required only 1/4^th as many lines of code, was 28x faster (that's 2700%), and supported 7.6x as many concurrent users as J2EE, with only 1/6^th as much processor utilization.  Click here to review the results, download the code, and run the .NET Pet Shop yourself.
  

Enhanced Reliability
ASP.NET ensures that your application is always available to your users.

• Memory Leak, DeadLock and Crash Protection.  ASP.NET automatically detects and recovers from errors like deadlocks and memory leaks to ensure your application is always available to your users. 
  
  For example, say that your application has a small memory leak, and that after a week the leak has tied up a significant percentage of your server's virtual memory.  ASP.NET will detect this condition, automatically start up another copy of the ASP.NET worker process, and direct all new requests to the new process.  Once the old process has finished processing its pending requests, it is gracefully disposed and the leaked memory is released.  Automatically, without administrator intervention or any interruption of service, ASP.NET has recovered from the error.    

Easy Deployment
ASP.NET takes the pain out of deploying server applications.

• "No touch" application deployment.  ASP.NET dramatically simplifies installation of your application.  With ASP.NET, you can deploy an entire application as easily as an HTML page: just copy it to the server.  No need to run regsvr32 to register any components, and configuration settings are stored in an XML file within the application.
  
  
• Dynamic update of running application.  ASP.NET now lets you update compiled components without restarting the web server.  In the past with classic COM components, the developer would have to restart the web server each time he deployed an update.  With ASP.NET, you simply copy the component over the existing DLL -- ASP.NET will automatically detect the change and start using the new code. 
  
  
• Easy Migration Path.  You don't have to migrate your existing applications to start using ASP.NET.  ASP.NET runs on IIS side-by-side with classic ASP on Windows 2000 and Windows XP platforms.  Your existing ASP applications continue to be processed by ASP.DLL, while new ASP.NET pages are processed by the new ASP.NET engine.  You can migrate application by application, or single pages.  And ASP.NET even lets you continue to use your existing classic COM business components.

New Application Models
ASP.NET extend your application's reach to new customers and partners.

• XML Web Services.  XML Web services allow applications to communicate and share data over the Internet, regardless of operating system or programming language.  ASP.NET makes exposing and calling XML Web Services simple.
  
  Any class can be converted into an XML Web Service with just a few lines of code, and can be called by any SOAP client. 
  
  Likewise, ASP.NET makes it incredibly easy to call XML Web Services from your application.  No knowledge of networking, XML, or SOAP is required.
  
  
• Mobile Web Device Support.  ASP.NET Mobile Controls let you easily target cell phones, PDAs -- over 80 mobile Web devices -- using ASP.NET.  You write your application just once, and the mobile controls automatically generate WAP/WML, HTML, or iMode as required by the requesting device.