August 17, 2014- The .NET Framework 4 works side by side with older Framework versions. Applications that are based on earlier versions of the Framework will continue to run on the version targeted by default.
.NET Framework 4 includes the following new features and improvements:
- Improvements in CLR and BCL
- Improvements in ADO.NET
- Enhancements to ASP.NET
- Improvements in Windows Presentation Foundation
- Improvements to Windows Workflow Foundation and Windows Communication Foundation