Microsoft .NET Framework 4.5.1 Final [Multi/Ru]

• Microsoft Visual Studio (C#, Visual Basic .NET, Managed C++),
  
• SharpDevelop,
  
• MonoDevelop,
  
• Eclipse,
  
• Borland Developer Studio (Delphi for .NET, C#),
  
• PascalABC.NET и т. д.

Приложения также можно разрабатывать в текстовом редакторе и использовать консольный компилятор.

Подобно технологии Java, среда разработки .NET создаёт байт-код, предназначенный для исполнения виртуальной машиной. Входной язык этой машины в .NET называется MSIL (Microsoft Intermediate Language), или CIL (Common Intermediate Language, более поздний вариант), или просто IL. Применение байт-кода позволяет получить кроссплатформенность на уровне скомпилированного проекта (в терминах .NET: сборка), а не только на уровне исходного текста, как, например, в С. Перед запуском сборки в среде исполнения CLR байт-код преобразуется встроенным в среду JIT-компилятором (just in time, компиляция на лету) в машинные коды целевого процессора. Также существует возможность скомпилировать сборку в родной (native) код для выбранной платформы с помощью поставляемой вместе с .NET Framework утилиты NGen.exe.

Следует отметить, что один из первых JIT-компиляторов для Java был также разработан фирмой Microsoft. Современная технология динамической компиляции позволяет достигнуть уровня быстродействия, аналогичного традиционным «статическим» компиляторам (например, C++), и вопрос быстродействия зачастую зависит от качества того или иного компилятора.

Core new features and enhancements:

• Automatic binding redirection for assemblies. Starting with Visual Studio 2013, when you compile an app that targets the .NET Framework 4.5.1, binding redirects may be added to the app configuration file if your app or its components reference multiple versions of the same assembly. You can also enable this feature for projects that target older versions of the .NET Framework. For more information, see How to: Enable and Disable Automatic Binding Redirection.
  
• Ability to collect diagnostics information to help developers improve the performance of server and cloud applications. For more information, see the WriteEventWithRelatedActivityId and WriteEventWithRelatedActivityIdCore methods in the EventSource class.
  
• Ability to explicitly compact the large object heap (LOH) during garbage collection. For more information, see the GCSettings.LargeObjectHeapCompactionMode property.
  
• Additional performance improvements such as ASP.NET app suspension, multi-core JIT improvements, and faster app startup after a .NET Framework update. For details, see the .NET Framework 4.5.1 announcement and the ASP.NET app suspend blog post.

Improvements when debugging your .NET Framework apps in Visual Studio 2013:

• Return values in the Visual Studio debugger. When you debug a managed app in Visual Studio 2013, the Autos window displays return types and values for methods. This information is available for desktop, Windows Store, and Windows Phone apps. For more information, see Examine return values of method calls in the MSDN Library.
  
• Edit and Continue for 64-bit apps. Visual Studio 2013 supports the Edit and Continue feature for 64-bit managed apps for desktop, Windows Store, and Windows Phone. The existing limitations remain in effect for both 32-bit and 64-bit apps (see the last section of the Supported Code Changes (C#) article).
  
• Async-aware debugging. To make it easier to debug asynchronous apps in Visual Studio 2013, the call stack hides the infrastructure code provided by compilers to support asynchronous programming, and also chains in logical parent frames so you can follow logical program execution more clearly. A Tasks window replaces the Parallel Tasks window and displays tasks that relate to a particular breakpoint, and also displays any other tasks that are currently active or scheduled in the app. You can read about this feature in the "Async-aware debugging" section of the .NET Framework 4.5.1 announcement.
  
• Better exception support for Windows Runtime components. In Windows 8.1, exceptions that arise from Windows Store apps preserve information about the error that caused the exception, even across language boundaries. You can read about this feature in the "Windows Store app development" section of the .NET Framework 4.5.1 announcement.
  
  Starting with Visual Studio 2013, you can use the Managed Profile Guided Optimization Tool (Mpgo.exe) to optimize Windows Store apps as well as desktop apps.
  For new features in ASP.NET 4.5.1, see ASP.NET 4.5.1 and Visual Studio 2013 on the ASP.NET site.
  Note that the .NET Framework team has started continuous delivery of features such as immutable collections with NuGet. Features are released out of band (OOB) to expand platform support and to introduce new functionality. For more information, see The .NET Framework and Out-of-Band Releases.