PyTools is:
Python Tools for Visual Studio is a free & open source plug-in for Visual Studio 2010 from Microsoft's Technical Computing Group. PTVS enables developers to use all the major productivity features of Visual Studio to build Python code using either CPython or IronPython and adds new features such as using High Performance Computing clusters to scale your code. Together with one of the standard distros, you can turn Visual Studio into a powerful Technical Computing IDE...
Want it to work with ArcPy? Check this out.
