What's New in the .NET Framework Version 3.5 SP1

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

This topic contains information about new and enhanced features in the .NET Framework version 3.5 Service Pack 1.


New ASP.NET features include ASP.NET Dynamic Data, which provides a rich scaffolding framework that allows rapid data driven development without writing code, and an addition to ASP.NET AJAX that provides support for managing browser history (back button support). For more information, see What’s New in ASP.NET and Web Development.

Common Language Runtime

Core improvements to the common language runtime include the following:

  • Improved application startup and working set performance.

  • Better layout of .NET Framework native images.

  • Opting out of strong-name verification of fully trusted assemblies.

  • Better generated code that improves end-to-end application execution time.

  • Detecting approaching full garbage collections with Garbage Collection Notifications.

  • Opting for managed code to run in ASLR (Address Space Layout Randomization) if supported by the operating system.

  • Managed applications that are opened from network shares have the same behavior as native applications by running with full trust.

.NET Framework Client Profile

The .NET Framework Client Profile is a subset of the full .NET Framework that targets client applications. This improves the installation experience on computers that do not already have the .NET Framework installed.


Enhancements have been made that affect how integrated Windows authentication is handled by the HttpWebRequest, HttpListener, SmtpClient, SslStream, NegotiateStream, and related classes in the System.Net and related namespaces. Support was added for extended protection to enhance security. The changes to support extended protection are available only for applications on Windows 7. The extended protection features are not available on earlier versions of Windows. For more information, seeIntegrated Windows Authentication with Extended Protection.

Windows Presentation Foundation

Performance improvements have been made to Windows Presentation Foundation, including a faster startup time and improved performance for Bitmap effects. Additional functionality for Windows Presentation Foundation includes better support for line of business applications, native splash screen support, DirectX pixel shader support, and the new WebBrowser control.


ClickOnce application publishers can decide to opt out of signing and hashing as appropriate for their scenarios, developers can programmatically install ClickOnce applications that display a customized branding, and ClickOnce error dialog boxes support links to application-specific support sites on the Web. For more information about ClickOnce, see ClickOnce Deployment for Windows Forms Applications.

Accessing Data with ADO.NET

The .NET Framework Data Provider for SQL Server (System.Data.SqlClient) provides full support for all the new features of the SQL Server 2008 Database Engine. For more information about .NET Framework support for SQL Server 2008, see New Features in SQL Server 2008 (ADO.NET).

The ADO.NET Data Platform is a multi-release strategy to decrease the amount of coding and maintenance required for developers by enabling them to program against conceptual entity data models. This platform includes the ADO.NET Entity Framework, the Entity Data Model (EDM), Object Services, LINQ to Entities, Entity SQL, EntityClient, ADO.NET Data Services and Entity Data Model Tools. For more information, see ADO.NET Technology Options and Guidelines.

Windows Communication Foundation

The Windows Communication Foundation now makes the DataContract Serializer easier to use by providing improved interoperability support, enhancing the debugging experience in partial trust scenarios, and extending syndication protocol support for wider usage in Web 2.0 applications.

Windows Forms Controls

The Microsoft.VisualBasic.PowerPacks namespace introduces the new DataRepeater control that displays data in a customizable list format. This namespace also includes new vector shapes.

See Also


.NET Framework 3.5 Architecture

What's New in ADO.NET

What's New in Windows Presentation Foundation Version 4

What's New in the .NET Framework Version 3.5

Other Resources

What’s New in ASP.NET and Web Development

Getting Started with the Entity Framework