Though there is one Python implementation which is by far the most
popular, there are some alternate implementations which are of
particular interest to different audiences.
Known implementations include:
CPython
This is the original and most-maintained implementation of Python,
written in C. New language features generally appear here first.
Jython
Python implemented in Java. This implementation can be used as a
scripting language for Java applications, or can be used to create
applications using the Java class libraries. It is also often used to
create tests for Java libraries. More information can be found at
the Jython website.
Python for .NET
This implementation actually uses the CPython implementation, but is a
managed .NET application and makes .NET libraries available. This was
created by Brian Lloyd. For more information, see the Python
for .NET home page.
IronPython
An alternate Python for .NET. Unlike Python.NET, this is a complete
Python implementation that generates IL, and compiles Python code
directly to .NET assemblies. It was created by Jim Hugunin, the
original creator of Jython. For more information, see the
IronPython website.
PyPy
An implementation of Python written in Python; even the bytecode
interpreter is written in Python. This is executed using CPython as
the underlying interpreter. One of the goals of the project is to
encourage experimentation with the language itself by making it easier
to modify the interpreter (since it is written in Python). Additional
information is available on the PyPy project's home
page.
Each of these implementations varies in some way from the language as
documented in this manual, or introduces specific information beyond
what's covered in the standard Python documentation. Please refer to
the implementation-specific documentation to determine what else you
need to know about the specific implementation you're using.
