I've never used turtle before, but that looks similar to Pickle and cPickle. The difference between those two is that since python is kinda slow, they redid the Pickle library with C (cPython) to make it alot faster.
cTurtle.py has nothing to do with C. It is simply someones hack of the turtle.py with a few extra methods added. See the beginning of file cTurtle.py for details. You can also run it, as it has a built-in demo.
It comes in two versions, one for Python2 and another for Python3.
Those modules are often written by instructors in colleges to keep their students from simply copying existing code, spreading confusion for the rest of us! There is a similar module out called graphics.py, that is a wrapper for Tkinter. Again nothing but a pain in the butt.