[fencepost]

If I worked at Microsoft?

I'd implement a Quicksort by checking within the existing codebases that I had access to and that were in the same language to see if it had already been done, then patch what I found to match my needs for comparisons, etc.

Note: one big reason for this is licensing - if it was developed in-house, odds are that licensing issues are a non-factor but if it came from "The Internets" then life may get strange. Strange is bad.