Microsoft .NET Framework 4.5.1 RC Developer Pack for Windows Server 2012, Windows Server 2008 R2 SP1, Windows Server 2008 SP2, Windows 8, Windows 7 SP1, and Windows Vista SP2

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What’s new in the .NET Framework 4.5.1 RC?

The .NET Framework 4.5.1 RC supports the writing of code in C#, Visual Basic, and F# programming languages, and includes these significant language and framework enhancements:

• Better performance and reliability
• ASP.NET application suspend and resume
• On-demand compaction of the large object heap
• 64-bit Edit and Continue
• Activity tracing and sampling
• SQL connection resiliency
• Managed return values

For more information about these and other features of the .NET Framework 4.5.1, see the .NET Framework Developer Center website and blog post. This version of the .NET Framework runs side-by-side with the Microsoft .NET Framework 3.5 Service Pack 1 (SP1) and earlier versions, but performs an in-place update for the .NET Framework 4 and the .NET Framework 4.5.

Command-line switches for this update

For more information about the various command-line switches that are supported by this update, see the "Command-Line options" section of the following MSDN website:

Supported languages for this update

For more information about the languages supported by this update, see the "Supported Languages for Developer Pack" section of the following MSDN website:

Restart requirement

You may have to restart the computer after you install this software if any affected files are being used. We recommend that you close all applications that are using the .NET Framework before you apply this update.