The main reason GVR said is "May be this is future of Python , but not now" . At that time pypy was already stable at 2.7.x version but python 2-3 split happen.

The main reason GVR said is "May be this is future of Python , but not now" . At that time pypy was already stable at 2.7.x version but python 2-3 split happen. PyPy team have to rewrite everything for Python3 and took them a while to catchup. I had managed to talk with one ex pypy developer that the main reason GVR and Python community do not promote much about PyPy is due to NIH - Not invented here - Since PyPy is developed by seperate but full time computer scientist and researchers, PHDs , not by the Guido community . https://pypy.org/people.html https://pypy.org/people.html One problem about popularity of pypy is they don't do any advertisement , promotion which I had critically voiced about it in their community - they moved to Github finally. Only other problem is CPython Ext , which is compatible but a little bit slower than CPython - that only pain point we have - which could be solved if there are more contributors and users using pypy. Actually Python , written in Python should be the main