Thanks for catching the missing utils.py file. I can explain the missing/commented statement in IOBinding.py. I found experimentally that if that statement is present, when you open a file on Windows the first line is off the top of the display, which can be quite confusing; this bug is not present on the Mac, and deleting the statement makes Windows work properly without affecting the Mac. The deletion of the statement was the very last correction Guilherme Polo made, and I got the correction into the patch I submitted but not into a less correct file at vpython.org.