Visual Studio and the .NET Framework
Applies To: Dynamics CRM 2013
This release of the Microsoft Dynamics CRM SDK for Microsoft Dynamics CRM 2013 and Microsoft Dynamics CRM Online is built on .NET Framework 4. When creating a managed code project you can use Microsoft Visual Studio 2010, 2012, or 2013 to build your .NET Framework 4 applications. You can choose to use a Microsoft Visual Studio Express edition for development, however, use of extensions is not supported in the Express edition so you will not be able to install the Developer Toolkit in that version of Microsoft Visual Studio. Use of the Developer Toolkit is recommended, but not required.
Use of the SDK with Microsoft .NET Framework 4.5 for managed code application development is not supported at this time. More information: Support for .NET Framework Versions. When a future release of CRM is released with .NET Framework 4.5 support, there will be a known breaking change in the Windows Identity Framework (WIF) namespace used by Microsoft Dynamics CRM SDK-based applications. Your applications may need to be updated due to this change. More information: Guidelines for Migrating an Application Built Using WIF 3.5 to WIF 4.5
For a complete statement of supported and unsupported development, see Supported extensions for Microsoft Dynamics CRM 2013.