.NET Framework 3.5

Version 3.5 of the .NET Framework was released on 2007, but it is not included with Windows Server 2008. As with .NET Framework 3.0, version 3.5 uses the CLR of version 2.0. In addition, it installs .NET Framework 2.0 SP1, (installs .NET Framework 2.0 SP2 with 3.5 SP1) and .NET Framework 3.0 SP1 (installs .NET Framework 3.0 SP2 with 3.5 SP1), which adds some methods and properties to the BCL classes in version 2.0 which are required for version 3.5 features such as Language Integrated Query (LINQ). These changes do not affect applications written for version 2.0, however.

As with previous versions, a new .NET Compact Framework 3.5 was released in tandem with this update in order to provide support for additional features on Windows Mobile and Windows Embedded CE devices.

The source code of the Base Class Library in this version has been partially released (for debugging reference only) under the Microsoft Reference Source License.

Changes since version 3.0

• New language features in C# 3.0 and VB.NET 9.0 compiler
• Adds support for expression trees and lambda methods
• Extension methods
• Expression trees to represent high-level source code at runtime.
• Anonymous types with static type inference
• Language Integrated Query (LINQ) along with its various providers
• LINQ to Objects
• LINQ to XML
• LINQ to SQL
• Paging support for ADO.NET
• ADO.NET synchronization API to synchronize local caches and server side datastores
• Asynchronous network I/O API .
• Peer-to-peer networking stack, including a managed PNRP resolver
• Managed wrappers for Windows Management Instrumentation and Active Directory APIs
• Enhanced WCF and WF runtimes, which let WCF work with POX and JSON data, and also expose WF workflows as WCF services. WCF services can be made stateful using the WF persistence model.
• Support for HTTP pipelining and syndication feeds.
• ASP.NET AJAX is included
• New System.CodeDom namespace.