title: Support multiple .NET Core versions on Mac OS X
body: <p>I need to develop both .NET Core <code>project.json</code>-based and <code>.csproj</code>-based applications on my Mac OS system. This is because certain environments only offer a down-level version of the .NET Core runtime, that I don't have direct control over.</p>
  
  <p>However, when I install a new version of the .NET SDK, it overwrites the old one. </p>
  
  <p><strong>Question</strong>: How can I install and reference multiple versions of the .NET Core SDK on my Mac?</p>