IronPython
- A fast Python implementation for .NET and Mono.
- http://www.codeplex.com/Wiki/View.aspx?ProjectName=IronPython

Python for .NET
- Package gives nearly seamless integration with .NET Common Language Runtime: CLR. Strong scripting tool, allows scripting or building full programs in Python, using .NET services and components coded in any language targeting CLR: Managed C++, C#, VB, JSc
- http://pythonnet.sourceforge.net/

CPython
- The original implementation of Python, written in C.
- http://python.org/download/

Boo
- New object-oriented statically typed language for Common Language Infrastructure (.NET, Mono), Python inspired syntax, focus on language and compiler extensibility.
- http://boo.codehaus.org/

Stackless Python
- An experimental implementation that supports continuations, generators, microthreads, and coroutines.
- http://www.stackless.com/

PyPy
- Development of a highly flexible Python implementation.
- http://codespeak.net/pypy/

Jython
- A 100 % Pure Java implementation of the Python language.
- http://sourceforge.net/projects/jython/