def _implementation():
    """Return a dict with the Python implementation and version.

    Provide both the name and the version of the Python implementation
    currently running. For example, on CPython 2.7.5 it will return
    {'name': 'CPython', 'version': '2.7.5'}.

    This function works best on CPython and PyPy: in particular, it probably
    doesn't work for Jython or IronPython. Future investigation should be done
    to work out the correct shape of the code for those platforms.
    """
    implementation = platform.python_implementation()

    if implementation == 'CPython':
        implementation_version = platform.python_version()
    elif implementation == 'PyPy':
        implementation_version = '%s.%s.%s' % (sys.pypy_version_info.major,
                                               sys.pypy_version_info.minor,
                                               sys.pypy_version_info.micro)
        if sys.pypy_version_info.releaselevel != 'final':
            implementation_version = ''.join([
                implementation_version, sys.pypy_version_info.releaselevel
            ])
    elif implementation == 'Jython':
        implementation_version = platform.python_version()  # Complete Guess
    elif implementation == 'IronPython':
        implementation_version = platform.python_version()  # Complete Guess
    else:
        implementation_version = 'Unknown'

    return {'name': implementation, 'version': implementation_version}