Aside from the official CPython distribution available from python.org, other distributions based on CPython include the following:
Anaconda from Continuum Analytics
ChinesePython Project: Translation of Python's keywords, internal types and classes into Chinese. Eventually allows a programmer to write Python programs in Chinese.
Win9xPython: Backport of mainline CPython 2.6/2.7 to old versions of Windows 9x/NT.
Portable Python: Run Python from USB device - no installation needed.
PyPy: a Python implementation in Python.
PythonLabsPython: an old name for the python.org distribution
Tiny Python (archived link) - not to be confused with tinypy