title: How to find what versions of C# and .NET/Mono are being used?
body: <p>You can use <code>System.Environment.Version</code> to the get the version of the CLR; how do you get the versions of C# and of the .NET or Mono framework currently being used?</p>
  
  <p>EDIT: I am NOT asking how to find whether you are using Mono or .NET. (The very first version of my question did ask that as a secondary question, but I deleted that almost immediately when I saw that question answered elsewhere.) The questions here are (1) how to figure out what version of C# you are working with, and (2) what version of .NET you have (as opposed to the version of the CLR, which <a href="http://msdn.microsoft.com/en-us/library/bb822049.aspx" rel="nofollow">isn't the same thing</a>). </p>