The first version of the .NET Framework was released on 13 February 2002 for Windows 98, ME, NT 4.0, 2000, and XP. Mainstream support for this version ended on 10 July 2007, and extended support ended on 14 July 2009, with the exception of Windows XP Media Center and Tablet PC editions.
On 19 July 2001, the tenth anniversary of the release of Visual Basic, .NET Framework 1.0 Beta 2 was released.
.NET Framework 1.0 is supported on Windows 98, ME, NT 4.0, 2000, XP, and Server 2003. Applications utilizing .NET Framework 1.0 will also run on computers with .NET Framework 1.1 installed, which supports additional operating systems.
Version 1.1 is the first minor .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 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 ended on 8 October 2013. .NET Framework 1.1 is the last version to support Windows NT 4.0.
Installing .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.
Changes in 1.1 include:Built-in support for mobile ASP.NET controls, which was previously available as an add-on
Enables Windows Forms assemblies to execute in a semi-trusted manner from the Internet
Enables Code Access Security in ASP.NET applications
Built-in support for ODBC and Oracle Database, which was previously available as an add-on
.NET Compact Framework, a version of the .NET Framework for small devices
Internet Protocol version 6 (IPv6) support
.NET Framework 1.1 is supported on Windows 98, ME, NT 4.0, 2000, XP, Server 2003, Vista, and Server 2008.
Version 2.0 was released on 22 January 2006. It was also released along with Visual Studio 2005, Microsoft SQL Server 2005, and BizTalk 2006. A software development kit for this version was released on 29 November 2006. It was the last version to support Windows 98 and Windows Me.
.NET Framework 2.0 with Service Pack 2 requires Windows 2000 with SP4 plus KB835732 or KB891861 update, Windows XP with SP2 plus Windows Installer 3.1. It is the last version to support Windows 2000 although there have been some unofficial workarounds to use a subset of the functionality from Version 3.5 in Windows 2000.
Changes in 2.0 include:Full 64-bit computing support for both the x64 and the IA-64 hardware platforms
Numerous API changes
Microsoft SQL Server integration: 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 and assembly loading. 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
Common Language Runtime (CLR) 2.0
Language support for generics built directly into the .NET CLR
.NET Framework 2.0 is supported on Windows 98, ME, 2000, XP, Server 2003, Vista, Server 2008, and Server 2008 R2. Applications utilizing .NET Framework 2.0 will also run on computers with .NET Framework 3.0 or 3.5 installed, which supports additional operating systems.
.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. 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 same CLR as .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 XAML markup language, which uses 3D computer graphics hardware and Direct3D technologies
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 building 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 3.0 is supported on Windows XP, Server 2003, Vista, Server 2008, and Server 2008 R2. Applications utilizing .NET Framework 3.0 will also run on computers with .NET Framework 3.5 installed, which supports additional operating systems.
Version 3.5 of the .NET Framework was released on 19 November 2007. As with .NET Framework 3.0, version 3.5 uses Common Language Runtime (CLR) 2.0, that is, the same version as .NET Framework version 2.0. In addition, .NET Framework 3.5 also installs .NET Framework 2.0 SP1 and 3.0 SP1 (with the later 3.5 SP1 instead installing 2.0 SP2 and 3.0 SP2), 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 Framework Class Library in this version has been partially released (for debugging reference only) under the Microsoft Reference Source License.
.NET Framework 3.5 is supported on Windows XP, Server 2003, Vista, Server 2008, 7, Server 2008 R2, 8, Server 2012, 8.1, Server 2012 R2, 10, and Server 2016.
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 used 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).
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.
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)
Introduced Common Language Runtime (CLR) 4.0
.NET Framework 4.0 is supported on Windows Server 2003, Vista, Server 2008, 7 and Server 2008 R2. Applications utilizing .NET Framework 4.0 will also run on computers with .NET Framework 4.5 or 4.6 installed, which supports additional operating systems.
Microsoft announced the intention to ship .NET Framework 4 on 29 September 2008. The Public Beta was released on 20 May 2009.
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 22 March 2010. This launch date was subsequently delayed to 12 April 2010.
On 10 February 2010, a release candidate was published: Version:RC.
On 12 April 2010, the final version of .NET Framework 4.0 was launched alongside the final release of Microsoft 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.
On 19 October 2011, version 4.0.2 was released supporting some new features of Microsoft SQL Server.
Version 4.0.3 was released on 4 March 2012.
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 was released on 15 August 2012; a set of new or improved features were added into this version. The .NET Framework 4.5 is only supported on Windows Vista or later. The .NET Framework 4.5 uses Common Language Runtime 4.0, with some additional runtime features.
.NET Framework 4.5 is supported on Windows Vista, Server 2008, 7, Server 2008 R2, 8, Server 2012, 8.1 and Server 2012 R2. Applications utilizing .NET Framework 4.5 will also run on computers with .NET Framework 4.6 installed, which supports additional operating systems.
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.
Native support for Zip compression (previous versions supported the compression algorithm, but not the archive format).
Ability to customize a reflection context to override default reflection behavior through the CustomReflectionContext class.
New asynchronous features were added to the C# and Visual Basic languages. These features add a task-based model for performing asynchronous operations, implementing futures and promises.
The Managed Extensibility Framework or MEF is a library for creating lightweight, extensible applications. It allows application developers to discover and use extensions with no configuration required. It also lets extension developers easily encapsulate code and avoid fragile hard dependencies. MEF not only allows extensions to be reused within applications, but across applications as well.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 Anti-XSS 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
Improved internationalization and IPv6 support
RFC-compliant URI support
Support for internationalized domain name (IDN) parsing
Support for Email Address Internationalization (EAI)
The release of .NET Framework 4.5.1 was announced on 17 October 2013 along Visual Studio 2013. This version requires Windows Vista SP2 and later and is included with Windows 8.1 and Windows Server 2012 R2. New features of .NET Framework 4.5.1:Debugger support for X64 edit and continue (EnC)
Debugger support for seeing managed return values
Async-aware debugging in the Call Stack and Tasks windows
Debugger support for analyzing .NET memory dumps (in the Visual Studio Ultimate SKU)
Tools for .NET developers in the Performance and Diagnostics hub
Code Analysis UI improvements
ADO.NET idle connection resiliency
The release of .NET Framework 4.5.2 was announced on 5 May 2014. For Windows Forms applications, improvements were made for high DPI scenarios. For ASP.NET, higher reliability HTTP header inspection and modification methods are available as is a new way to schedule background asynchronous worker tasks.
.NET Framework 4.6 was announced on 12 November 2014. It was released on 20 July 2015. It supports a new just-in-time compiler (JIT) for 64-bit systems called RyuJIT, which features higher performance and support for SSE2 and AVX2 instruction sets. WPF and Windows Forms both have received updates for high DPI scenarios. Support for TLS 1.1 and TLS 1.2 has been added to WCF. This version requires Windows Vista SP2 or later.
The cryptographic API in .NET Framework 4.6 uses the latest version of Windows CNG cryptography API. As a result, NSA Suite B Cryptography is available to .NET Framework. Suite B consists of AES, the SHA-2 family of hashing algorithms, elliptic curve Diffie–Hellman, and elliptic curve DSA.
.NET Framework 4.6 is supported on Windows Vista, Server 2008, 7, Server 2008 R2, 8, Server 2012, 8.1, Server 2012 R2, 10 and Server 2016. However, .NET Framework 4.6.1 and 4.6.2 drops support for Windows Vista and Server 2008.
The release of .NET Framework 4.6.1 was announced on 30 November 2015. This version requires Windows 7 SP1 or later. New features and APIs include:WPF improvements for spell check, support for per-user custom dictionaries and improved touch performance.
Enhanced support for Elliptic Curve Digital Signature Algorithm (ECDSA) X509 certificates.
Added support in SQL Connectivity for AlwaysOn, Always Encrypted and improved connection open resiliency when connecting to Azure SQL Database.
Azure SQL Database now supports distributed transactions using the updated System.Transactions APIs .
Many other performance, stability, and reliability related fixes in RyuJIT, GC, WPF and WCF.
The preview of .NET Framework 4.6.2 was announced on March 30, 2016. It was released on August 2, 2016. This version requires Windows 7 SP1 or later. New features include:Support for paths longer than 260 characters
Support for FIPS 186-3 DSA in X.509 certificates
TLS 1.1/1.2 support for ClickOnce
Support for localization of data annotations in ASP.NET
Enabling .NET desktop apps with Project Centennial
Soft keyboard and per-monitor DPI support for WPF