title: Is the Managed Extensibility Framework (MEF) what ASP.NET Core 2 uses internally for IoC?
body: <p>I am trying to gauge if Managed Extensibility Framework (MEF) is something I can use for extending an ASP.NET Core 2.x MVC website.  I saw ExtCore also.  My desire is to use it to build infrastructure for plugins in my application.</p>
  
  <p>What I cannot figure out is if MEF is legacy from Silverlight or if MEF is what Core actually uses for it's IoC.  I know MEF is in CoreFX, but that's all I know for sure.</p>
  
  <p>I'd like to use MS's IoC DI here if it is viable and not legacy.  Is MEF legacy or is it used by Core itself?</p>
  
  <p>Some questions I looked at, most were very old,</p>
  
  <p><a href="https://stackoverflow.com/questions/28801312/is-there-a-replacement-for-mef-in-net-core-or-asp-net-5">Is there a replacement for MEF in .NET Core (or ASP.NET 5)</a></p>
  
  <p><a href="https://stackoverflow.com/questions/41269797/in-asp-net-core-does-the-ioc-asp-startup-class-solve-what-the-managed-extensibi">In ASP.NET Core, does the IoC ASP Startup Class solve what the Managed Extensibility Framework solved with a catalog and container?</a>
   (The last one is a question I asked at the end of 2016.)</p>