A friend of mine just got hired at a startup to build a new language. He was the one that convinced me that Python with slightly modified semantics is actually something people are totally comfortable with. Most of the pain is around all of the little idiosyncrasies of a Python, like if you divide two integers and Python two, you get an int. But if you divide them in Python three, you get a float,. Like these little details can be a lot of work.