IronPython is a project that implements the dynamic object-oriented Python language on top of the CLI.  IronPython is both well integrated with the .NET Framework and is a true implementation of the Python language.  .NET integration means that this rich programming framework is available to Python developers and that they can interoperate with other .NET languages and tools.  All of Python’s dynamic features (such as, an interactive interpreter and the ability to dynamically modify objects) are available.

If you're curious about the interesting history of IronPython, see Jim Hugunin's blog.  

Grab IronPython 1.0 today!