Comment by mschaef

> No offense, but I don't think you looked too hard. There are lots of calls that could be used to do things in a more performant way,

Undocumented API calls were rumored to be a big deal even back in the Windows 3.x days. I remember reading through this at the time looking for the 'smoking gun'.

https://www.amazon.com/Undocumented-Windows-Programmers-Micr...

There were some cute and offensive names, and a few interesting details about the internal implementation of Windows, but nothing that would've been hugely beneficial.

Things might well have changed since then. (Both at Microsoft and at Apple, where their software is definitely allowed to do things that third party software is not.)