.NET Framework 3.5:

The .NET Framework 3.5 introduces new features for the technologies in 2.0 and 3.0 and additional technologies in the form of new assemblies. LINQ (Language Integrated Query), ASP.NET AJAX and new compilers for c#, Visual Basic and C++ are the technologies introduced in the .NET Framework 3.5.
     .NET Framework 3.5 = Features of 3.0+ ADO.NET entity Framework + LINQ

Changes in 3.5 on comparison with 3.0:

•   New language features in C# 3.0 and VB.NET 9.0 compiler.

•   An anonymous type with static type inference was introduced.

•  Language Integrated Query (LINQ)  was introduced along with its various providers

·         LINQ to Objects

·         LINQ to XML

·         LINQ to SQL

•   Support for paging to ADO.NET was introduced.

•   Peer-to-peer networking stack, including a managed PNRP resolver.

•   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.

.NET Framework 3.0:

                .NET Framework 3.0, formerly called WinMax was released on 21 November 2006. It includes a new set of Managed Code  APIs. There are no major architectural changes included with this release.

            .NET Framework 3.0 = .net 2.0 Features + WF + WPF +WCF + Cardspace

Changes in 3.0 on comparison with 2.0:

•  Windows Workflow Foundation (WF): It is a Microsoft technology for defining, executing, and managing workflows. This technology was first released in November 2006 as a part of .NET Framework 3.0. Windows Workflow Foundation allows for building of task automation and integrated transactions.

• Windows Presentation Foundation (WPF): It is a graphical subsystem for rendering user interfaces in Windows-based applications. WPF attempts to provide a consistent programming model for building applications and provides a clear separation between the user interface and the business logic.

•  Windows Communication Foundation (WCF): It is a service-oriented messaging system which allows programs to interoperate locally or remotely similar to web services.

•  Windows CardSpace: It is a software component which securely stores a person's digital identities and provides a unified interface for choosing the identity for a particular transaction, such as logging in to a website.

.NET Framework 2.0:

               The Microsoft.NET framework of Version 2.0 extends the .NET framework of Version 1.1.This version is released on 7 November 2005. It includes the official languages C#, Visual Basic.NET and J# and the Development environment.
Changes in 2.0 on comparison with 1.1:

• Support for 64 bit platform application development is introduced.

• New features like user defined data types, asynchronous database operations, XML data types, large value types are introduced in ADO.NET.

• A number of new features have been added to ASP.NET such as new controls for development of dynamic web pages

• Enhancements have been made to classes and tools that support interoperability with COM.

• Generics and Generic Collection are introduced.

• .NET Framework Remoting now supports IPv6 addresses and the exchange of generic types.

.NET Framework 1.1:

              This is the first major .NET Framework upgrade. This is the first version of the .NET Framework to be included as part of the Windows operating system, shipping with Windows Server 2003.
Changes in 1.1 on comparison with 1.0:

• Built-in support for mobile ASP.NET controls. Previously available as an add-on for .NET Framework, now part of the framework.

• Security changes-enable Windows Forms assemblies to execute in a semi-trusted manner from the Internet, and enable Code Access Security in ASP.NET applications.

• Built-in support for ODBC and Oracle databases. Previously available as an add-on for .NET Framework 1.0, now part of the framework.

• .NET Compact Framework – a version of the .NET Framework for small devices.

• Internet Protocol version 6 (IPv6) support.

• Numerous API changes.

.NET Framework 1.0:-

 .NET Framework 1.0 is the first release of the .NET Framework, released on 13th February 2002 and available for Windows 98, Me, NT 4.0,2000 and XP.
Features of .NET Framework 1.0:

• Enterprise Services: Object management is done through the enterprise services. This allowed the objects to build security around them, managing the transaction without the necessary for recompiling the code.

• Data Access: Data access is efficiently managed by Managed Providers. This managed provider consists of all the data providers and drivers. For example: If we are working with sql then sql provider will provide the drivers. If we are working with oracle then oracle provider will provide the drivers. So, there is no need to worry of changing the drivers when our database changes. This managed providers will efficiently manages the drivers.

• User Interface: .NET Framework 1.0 introduced the concept of Win Forms as objects. They also introduced the object model in ASP.NET, allowing us to develop web forms in an object oriented fashion. They also introduced the Smart Client for Rich Interactive Application development.

Versions of .Net Framework:

                           Microsoft started development on the .NET Framework in the late 1990s originally under the name of Next Generation Windows Services (NGWS). The .Net Framework is first released in beta in November 2000 and development continues today. 

1) .NET Framework 1.0

2) .NET Framework 1.1 

3) .NET Framework 2.0

4) .NET Framework 3.0

5) .NET Framework 3.5

6) .NET Framework4.0