.NET Framework Developer Center

Getting Started

About .NET

.NET Framework Conceptual Overview

Get .NET

Learning Resources

Download .NET Framework 3.5 SP1

The .NET Framework 3.5 Service Pack 1 (SP1) delivers more controls, improved start-up performance, AJAX support, and powerful new graphics features for client development. Visit the .NET Framework downloads page for more information.

Download the .NET Framework 4 Release Candidate

.NET Framework Technologies

Windows Presentation Foundation (WPF)
Use WPF for building applications and high fidelity experiences in Windows Vista.

Windows Communication Foundation (WCF)
Use WCF for building and running connected systems.

Windows Workflow Foundation (WF)
Use WF for building workflow-enabled applications on Windows.

Windows Forms
Use Windows Forms for building smart client applications.

.NET Services
Use .NET Services to connect cloud-based and cloud-aware applications.

ASP.NET
ASP.NET is a free technology for building dynamic web applications.

Base Class Libraries (BCL)
The BCL provides the fundamental building blocks for any application.

Common Language Runtime (CLR)
The CLR is the .NET Framework run-time environment.

Data Access
Use Entity Framework, Data Services, or ADO.NET to access data sources from your .NET apps.

.NET Compact Framework
Use .NET Compact Framework to build applications for Windows CE devices.

.NET Micro Framework
Use the .NET Micro Framework to develop for resource-constrained devices.

.NET Framework Highlights

You’re Hearing About Windows Phone 7 Series—Now Learn About It at MIX10
Everything you want to know about Windows Phone 7 Series is at MIX10. All attendees will receive access to the Windows Phone development tools, and free developer support.

CLR Inside Out: Migrating an APTCA Assembly to .NET Framework 4
The CLR security model in the Microsoft .NET Framework 4 has undergone some substantial changes, including the adoption of ”Level2” transparency, similar to the Silverlight security model. Mike Rousos provides an in-depth explanation of how that will impact authors of AllowPartiallyTrustedCallers (A... more

Announcing Windows Server AppFabric Beta 2!
The Beta 2 of Windows Server AppFabric - a set of application services focused on improving the speed, scale, and management of Web, Composite, and Enterprise applications - is now available. If you are a developers or IT professional building ASP.NET applications or applications that use WCF or WF... more

Featured Library Content

Important updates and highlights of .NET Framework content in the MSDN Library.

ASP.NET User Controls Overview
Learn how to create your own customized ASP.NET controls.
Tuesday, Mar 9 by Microsoft

Connecting to Databases in ASP.NET
Learn how to use data source controls, or write code to perform data access yourself using ADO.NET c... more
Tuesday, Mar 9 by Microsoft

Create an ASP.NET MVC Project with Unit Tests in Visual Studio
Test-driven development (TDD) with ASP.NET MVC. Create an ASP.NET MVC project that contains unit tes... more
Tuesday, Mar 9 by Microsoft

More .NET Framework Library Content...

More .NET Framework Resources

	.NET Framework 4 Release Candidate is Here Visual Studio 2010 and .NET Framework 4 mark the next generation of developer tools from Microsoft. Be sure to download the Release Candidate and let us know what you think.
	Give Us Your Feedback on .NET Framework Documentation Help us help you by taking 10 minutes to fill out our Content Survey on how to improve the Visual Studio and .NET Framework documentation.
	Channel 9 Videos Watch videos and connect with your peers.
	Code Gallery Find the latest .NET code samples or upload your own.
	CodePlex Find open source projects on CodePlex or start your own.
	MSDN Magazine Read in-depth articles about .NET.
	patterns & practices Use Microsoft's proven practices for software engineering.