title: What Sorting Algorithm Is Used By LINQ "OrderBy"?
body: <p>Evidently LINQ's "OrderBy" had originally been specified as unstable, but by the time of Orca it was specified as stable.  Not all documentation has been updated accordingly - consider these links:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/1209935/orderby-and-orderbydescending-are-stable">Jon Skeet on OrderBy stability</a></li>
  <li><a href="https://stackoverflow.com/questions/2786930/linq-quicksort-is-unstable-except-when-cascading">Troy Magennis on OrderBy stability</a></li>
  </ul>
  
  <p>But if LINQ's OrderBy is now "stable," then it means it is not using a quicksort (which is inherently unstable) even though some documentation (e.g. Troy's book) says it is.  So my question is: if not quicksort, then what is the actual algorithm LINQ's orderBy is using?</p>