Difference between .NET Framework 2.0/3.0/3.5/4.0

.NET FrameWork 2. 0 Features:

• Generics
• Anonymous methods
• Partial class
• Nullable type
• The new API gives a fine grain control on the behavior of the runtime with regards to multithreading, memory allocation, assembly loading and more
• Full 64-bit support for both the x64 and the IA64 hardware platforms
• New personalization features for ASP.NET, such as support for themes, skins and webparts.
• .NET Micro Framework
• Data Tables

.NET Framework 3.0 Features:

Also called WinFX,includes a new set of managed code APIs that are an integral part of Windows Vista and Windows Server 2008 operating systems and provides

• Windows Communication Foundation (WCF) – formerly called Indigo; a service-oriented messaging system which allows programs to interoperate locally or remotely similar to web services
• Windows Presentation Foundation (WPF) -  formerly called Avalon; a new user interface subsystem and API based on XML and vector graphics, which uses 3D computer graphics hardware and Direct3D technologies.
• Windows Workflow Foundation (WF) allows for building of task automation and integrated transactions using workflows.
• Windows CardSpace, formerly called InfoCard; 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 3.5 Features:

• Language Integrated Query (LINQ)  for SQL, XML, Dataset, Object
• Addin system
• p2p base class
• Active directory
• ASP.NET Ajax
• Anonymous types with static type inference
• Paging support for ADO.NET
• ADO.NET synchronization API to synchronize local caches and server side data stores
• Asynchronous network I/O API
• Support for HTTP pipelining and syndication feeds.
• New System.CodeDom namespace

.NET Framework 4.0 Features:

• Common Language Runtime (CLR)  – The following sections describe new features in security, parallel computing, performance and diagnostics, dynamic language runtime, and other CLR-related technologies
• Base Class Libraries
• Networking  – 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
• Web  – The following sections describe new features in ASP.NET core services, Web Forms, Dynamic Data, and Visual Web Developer.
• Client  – The following sections describe new features in Windows Presentation Foundation (WPF) and Managed Extensibility Framework (MEF).
• Data
• Communications  – Windows Communication Foundation (WCF) provides the new features and enhancements described in the following sections.
• Workflow – Windows Workflow Foundation (WF) in .NET Framework 4.0 changes several development paradigms from earlier versions. Workflows are now easier to create, execute, and maintain.