The title says it all: what CLR version is / will be needed to run C# 6 programs? The CLR version is interesting to find out the system requirements and supported operating systems.
I googled [1] [2] and had a look at Wikipedia and MSDN but could not find the information.
C # 6 language enhancements is compatible to .net framework starting from 2.0 to 4.6. It does not require any higher version of .net framework but need higher version of Visual studio such as VS 2015. C# 6 is also available to VS 2013 with addon https://github.com/dotnet/roslyn
In order to have C# 6 you need:
VS 2013 runs on .
NET 4.5.1
so I guess the answer to your Question is4.5.1
It is version 4 of CLR that is used. If you test
Environment.Version
in Visual Studio "14" CTPs you will get:With code:
Also if you look at Common Language Runtime (CLR) on MSDN you will find: