.NET Framework version history
||This article has an unclear citation style. (May 2013)|
Microsoft started development on the .NET Framework in the late 1990s originally under the name of Next Generation Windows Services (NGWS). By late 2000 the first beta versions of .NET 1.0 were released.
Version 3.0 of the .NET Framework is included with Windows Server 2008 and Windows Vista. Version 3.5 is included with Windows 7, and can also be installed on Windows XP and the Windows Server 2003 family of operating systems. On 12 April 2010, .NET Framework 4 was released alongside Visual Studio 2010.
The .NET Framework family also includes two versions for mobile or embedded device use. A reduced version of the framework, the .NET Compact Framework, is available on Windows CE platforms, including Windows Mobile devices such as smartphones. Additionally, the .NET Micro Framework is targeted at severely resource-constrained devices.
|Generation||Version number||Release date||Development tool||Distributed with|
|1.0||1.0.3705.0||2002-02-13||Visual Studio .NET||N/A|
|1.1||1.1.4322.573||2003-04-24||Visual Studio .NET 2003||Windows Server 2003|
|2.0||2.0.50727.42||2005-11-07||Visual Studio 2005||Windows Server 2003 R2|
|3.0||3.0.4506.30||2006-11-06||Expression Blend||Windows Vista, Windows Server 2008|
|3.5||3.5.21022.8||2007-11-19||Visual Studio 2008||Windows 7, Windows Server 2008 R2|
|4.0||4.0.30319.1||2010-04-12||Visual Studio 2010||N/A|
|4.5||4.5.50709.17929||2012-08-15||Visual Studio 2012||Windows 8, Windows Server 2012|
A more complete listing of the releases of the .NET Framework may be found on the List of .NET Framework versions.
.NET Framework 1.0 
This is the first release of the .NET Framework, released on 13 February 2002 and available for Windows 98, Me, NT 4.0, 2000, and XP. Mainstream support by Microsoft for this version ended 10 July 2007, and extended support ended 14 July 2009, with the exception of XP Media Center and Tablet PC editions.
.NET Framework 1.1 
This is the first major .NET Framework upgrade. It is available on its own as a redistributable package or in a software development kit, and was published on 3 April 2003. It is also part of the second release of Microsoft Visual Studio .NET (released as Visual Studio .NET 2003). This is the first version of the .NET Framework to be included as part of the Windows operating system, shipping with Windows Server 2003. Mainstream support for .NET Framework 1.1 ended on 14 October 2008, and extended support ends on 8 October 2013. Since .NET 1.1 is a component of Windows Server 2003, extended support for .NET 1.1 on Server 2003 will run out with that of the OS – currently 14 July 2015. .NET 1.1 is the last available version for Windows NT 4.0.
If .NET Framework 1.0 is removed, installing only .NET Framework 1.1 also provides the system support for version 1.0, except in rare instances where an application will not run because it checks the version number of a library.[dead link]
Changes in 1.1 in 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 2.0 
- The 2.0 Redistributable Package can be downloaded for free from Microsoft, and was published on 22 January 2006.
- The 2.0 Software Development Kit (SDK) can be downloaded for free from Microsoft.
- It is included as part of Visual Studio 2005 and Microsoft SQL Server 2005.
- Version 2.0 without any Service Pack is the last version with support for Windows 98 and Windows Me. Version 2.0 with Service Pack 2 is the last version with official support for Windows 2000 although there have been some unofficial workarounds published online to use a subset of the functionality from Version 3.5 in Windows 2000. Version 2.0 with Service Pack 2 requires Windows 2000 with SP4 plus KB835732 or KB891861 update, Windows XP with SP2 or later and Windows Installer 3.1 (KB893803-v2)
- It shipped with Windows Server 2003 R2 (not installed by default).
Changes in 2.0 in comparison with 1.1 
- Language support for generics built directly into the .NET CLR.
- Full 64-bit support for both the x64 and the IA-64 hardware platforms.
- Numerous API changes.
- SQL Server integration – .NET 2.0, VS 2005, and SQL Server 2005 are all tied together. This means that instead of using T-SQL, one can build stored procedures and triggers in any of the .NET-compatible languages.
- A new hosting API for native applications wishing to host an instance of the .NET runtime. The new API gives a fine grain control on the behavior of the runtime with regards to multithreading, memory allocation, assembly loading and more (detailed reference). It was initially developed to efficiently host the runtime in Microsoft SQL Server, which implements its own scheduler and memory manager.
- Many additional and improved ASP.NET web controls.
- New data controls with declarative data binding.
- New personalization features for ASP.NET, such as support for themes, skins, master pages and webparts.
- .NET Micro Framework – a version of the .NET Framework related to the Smart Personal Objects Technology initiative.
- Membership provider
- Partial classes
- Nullable types
- Anonymous methods
- Data tables
.NET Framework 3.0 
.NET Framework 3.0, formerly called WinFX, was released on 21 November 2006. It includes a new set of managed code APIs that are an integral part of Windows Vista and Windows Server 2008 operating systems. It is also available for Windows XP SP2 and Windows Server 2003 as a download. There are no major architectural changes included with this release; .NET Framework 3.0 uses the Common Language Runtime of .NET Framework 2.0. Unlike the previous major .NET releases there was no .NET Compact Framework release made as a counterpart of this version. Version 3.0 of the .NET Framework shipped with Windows Vista. It also shipped with Windows Server 2008 as an optional component (disabled by default).
.NET Framework 3.0 consists of four major new components:
- Windows Presentation Foundation (WPF), formerly code-named Avalon; a new user interface subsystem and API based on XML and vector graphics, which uses 3D computer graphics hardware and Direct3D technologies. See WPF SDK for developer articles and documentation on WPF.
- Windows Communication Foundation (WCF), formerly code-named Indigo; a service-oriented messaging system which allows programs to interoperate locally or remotely similar to web services.
- Windows Workflow Foundation (WF) allows for building of task automation and integrated transactions using workflows.
- Windows CardSpace, formerly code-named 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 
Version 3.5 of the .NET Framework was released on 19 November 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.
Service Pack 1 
The .NET Framework 3.5 Service Pack 1 was released on 11 August 2008. This release adds new functionality and provides performance improvements under certain conditions, especially with WPF where 20–45% improvements are expected. Two new data service components have been added, the ADO.NET Entity Framework and ADO.NET Data Services. Two new assemblies for web development, System.Web.Abstraction and System.Web.Routing, have been added; these are used in the ASP.NET MVC Framework and, reportedly, will be utilized in the future release of ASP.NET Forms applications. Service Pack 1 is included with SQL Server 2008 and Visual Studio 2008 Service Pack 1. It also featured a new set of controls called "Visual Basic Power Packs" which brought back Visual Basic controls such as "Line" and "Shape". Version 3.5 SP1 of the .NET Framework shipped with Windows 7. It also shipped with Windows Server 2008 R2 as an optional component (disabled by default).
.NET Framework 3.5 SP1 Client Profile 
For the .NET Framework 3.5 SP1 there is also a new variant of the .NET Framework, called the ".NET Framework Client Profile", which at 28 MB is significantly smaller than the full framework and only installs components that are the most relevant to desktop applications. However, the Client Profile amounts to this size only if using the online installer on Windows XP SP2 when no other .NET Frameworks are installed or using Windows Update. When using the off-line installer or any other OS, the download size is still 250 MB.
.NET Framework 4 
Key focuses for this release are:
- Parallel Extensions to improve support for parallel computing, which target multi-core or distributed systems. To this end, technologies like PLINQ (Parallel LINQ), a parallel implementation of the LINQ engine, and Task Parallel Library, which exposes parallel constructs via method calls., are included.
- New Visual Basic .NET and C# language features, such as implicit line continuations, dynamic dispatch, named parameters, and optional parameters.
- Support for Code Contracts.
- Inclusion of new types to work with arbitrary-precision arithmetic (System.Numerics.BigInteger) and complex numbers (System.Numerics.Complex).
On 28 July 2009, a second release of the .NET Framework 4 beta was made available with experimental software transactional memory support. This functionality is not available in the final version of the framework.
On 19 October 2009, Microsoft released Beta 2 of the .NET Framework 4. At the same time, Microsoft announced the expected launch date for .NET Framework 4 as the 22 March 2010. This launch date was subsequently delayed to 12 April 2010.
On 12 April 2010, the final version of .NET Framework 4.0 was launched alongside the final release of Visual Studio 2010.
On 18 April 2011, version 4.0.1 was released supporting some customer-demanded fixes for Windows Workflow Foundation. Its design-time component, which requires Visual Studio 2010 SP1, adds a workflow state machine designer.
Windows Server AppFabric 
After the release of the .NET Framework 4, Microsoft released a set of enhancements, named Windows Server AppFabric, for application server capabilities in the form of AppFabric Hosting and in-memory distributed caching support.
.NET Framework 4.5 
.NET for Metro style apps 
Metro style apps are designed for specific form factors and leverage the power of the Windows operating system. A subset of the .NET Framework is available for building Metro style apps for Windows 8 using C# or Visual Basic. This subset is called .NET APIs for Metro style apps.
Framework Core 
Core Features 
- Ability to limit how long the regular expression engine will attempt to resolve a regular expression before it times out.
- Ability to define the culture for an application domain.
- Console support for Unicode (UTF-16) encoding.
- Support for versioning of cultural string ordering and comparison data.
- Better performance when retrieving resources.
- Zip compression improvements to reduce the size of a compressed file.
- Ability to customize a reflection context to override default reflection behavior through the CustomReflectionContext class.
Managed Extensibility Framework (MEF) 
- Support for generic types.
- Convention-based programming model that enables you to create parts based on naming conventions rather than attributes.
- Multiple scopes.
Asynchronous operations 
In the .NET Framework 4.5, new asynchronous features were added to the C# and Visual Basic languages. These features add a task-based model for performing asynchronous operations.
- Support for new HTML5 form types.
- Support for model binders in Web Forms. These let you bind data controls directly to data-access methods, and automatically convert user input to and from .NET Framework data types.
- Improved handling of client script through bundling and minification for improved page performance.
- Integrated encoding routines from the AntiXSS library (previously an external library) to protect from cross-site scripting attacks.
- Support for WebSocket protocol.
- Support for reading and writing HTTP requests and responses asynchronously.
- Support for asynchronous modules and handlers.
- Support for content distribution network (CDN) fallback in the ScriptManager control.
- Provides a new programming interface for HTTP applications: System.Net.Http namespace and System.Net.Http.Headers namespaces are added.
- Other improvements:
Windows Presentation Foundation (WPF) 
- The new Ribbon control, which enables you to implement a ribbon user interface that hosts a Quick Access Toolbar, Application Menu, and tabs.
- The new INotifyDataErrorInfo interface, which supports synchronous and asynchronous data validation.
- New features for the VirtualizingPanel and Dispatcher classes.
- Improved performance when displaying large sets of grouped data, and by accessing collections on non-UI threads.
- Data binding to static properties, data binding to custom types that implement the ICustomTypeProvider interface and retrieval of data binding information from a binding expression.
- Repositioning of data as the values change (live shaping).
- Better integration between WPF and Win32 user interface components.
- Ability to check whether the data context for an item container is disconnected.
- Ability to set the amount of time that should elapse between property changes and data source updates.
- Improved support for implementing weak event patterns. Also, events can now accept markup extensions.
See also 
- "Framework Versions". Archived from the original on 4 May 2008.
- Microsoft. "Microsoft .NET Framework 3.5 Administrator Deployment Guide". Retrieved 26 June 2008.
- "Microsoft Product Lifecycle Search". Microsoft. Archived from the original on 5 September 2009. Retrieved 25 January 2008.
- ".NET Framework Developer Center – Frequently Asked Questions".
- "Microsoft .NET Framework 3.5 in Windows 2000". Archived from the original on 6 October 2011. Retrieved 6 October 2011.
- WinFX name change announcement Archived 21 June 2007 at WebCite
- ".NET Framework 3.0 Versioning and Deployment Q&A". Retrieved 1 June 2008.
- "Catching RedBits differences in .NET 2.0 and .NET 2.0SP1". Archived from the original on 30 April 2008. Retrieved 1 June 2008.
- Scott Guthrie (3 October 2007). "Releasing the Source Code for the NET Framework". Archived from the original on 7 September 2010. Retrieved 15 September 2010.
- "Visual Studio 2008 Service Pack 1 and .NET Framework 3.5 Service Pack 1". Archived from the original on 4 September 2008. Retrieved 7 September 2008.[dead link]
- Justin Van Patten (21 May 2008). ".NET Framework Client Profile". BCL Team Blog. MSDN Blogs. Archived from the original on 7 December 2008. Retrieved 30 September 2008.
- Jaime Rodriguez (20 August 2008). "Client profile explained..". Archived from the original on 5 February 2009. Retrieved 15 February 2009.
- S. Somasegar. "The world of multi and many cores". Archived from the original on 22 June 2007. Retrieved 1 June 2008.
- "Parallel LINQ: Running Queries On Multi-Core Processors". Retrieved 2 June 2008.
- "Parallel Performance: Optimize Managed Code For Multi-Core Machines". Retrieved 2 June 2008.
- S. Somasegar. "Visual Studio 2010 and .NET FX 4 Beta 1 ships!". Archived from the original on 27 May 2009. Retrieved 25 May 2009.
- "STM.NET on DevLabs". 27 July 2008. Archived from the original on 10 August 2009. Retrieved 6 August 2008.
- S. Somasegar. "Announcing Visual Studio 2010 and .NET FX 4 Beta 2". MSDN Blogs. Archived from the original on 22 October 2009. Retrieved 20 October 2009.
- Rob Caron. "Visual Studio 2010 and .NET Framework 4 Launch Date". MSDN Blogs. Archived from the original on 17 January 2010. Retrieved 13 January 2010.
- http://www.infoworld.com/d/developer-world/microsoft-offers-visual-studio-2010-release-candidate-643 Archived 21 May 2010 at the Wayback Machine
- "Update 4.0.1 for Microsoft .NET Framework 4 - Design-Time Update for Visual Studio 2010 SP1". Support.microsoft.com. 2012-06-25. Retrieved 2013-01-16.
- "Microsoft .NET Framework 4 Platform Update 1 - The .NET Endpoint - Site Home - MSDN Blogs". Blogs.msdn.com. 2011-04-19. Retrieved 2013-01-16.
- "Update 4.0.2 for Microsoft .NET Framework 4 – Runtime Update". Support.microsoft.com. 2012-06-14. Retrieved 2013-01-16.
- Windows Server AppFabric now Generally Available : AppFabric Blog : The Official Microsoft IIS Site
- "'Dublin' App Server coming to .NET 4". DevSource. Retrieved 27 April 2009.
- ".NET Framework 4 and Dublin Application Server". MSDN Blogs. Archived from the original on 10 May 2009. Retrieved 27 April 2009.
- Brandon Bray(MSDN Blogs). "Announcing the release of .NET Framework 4.5 RTM - Product and Source Code". Retrieved 15 August 2012.
- MSDN Library. "What's New in the .NET Framework 4.5". Retrieved 15 August 2012.
- Microsoft .NET Framework 4.5
- Standalone Installers .NET 4.5