Thanks for a better wording of my question! Even PyPy project doesn't have a goal of running py2-compatible and py3-compatible modules inside one interpreter:

Thanks for a better wording of my question! Even PyPy project doesn't have a goal of running py2-compatible and py3-compatible modules inside one interpreter: > At the end of the project, it will be possible to decide at translation time whether to build an interpreter which supports Python 2.7 or Python 3.2 and both versions will be nightly tested and available from nightly builds. http://pypy.org/py3donate.html http://pypy.org/py3donate.html