Yes, I skimmed it. But please note that I wrote about "simply" calling external executables, where you can just type the name of a program and have it run. Turtle doesn't even try to allow this (while PowerShell has it), instead going in the opposite direction:
> Most of the commands in this library do not actually invoke an external shell or program. Instead, they indirectly wrap other Haskell libraries that bind to C code.
proc and inshell. Did you check out the built-in tutorial?
http://hackage.haskell.org/package/turtle-1.0.0/docs/Turtle-...