How do I import .NET namespaces from assemblies other than System and Mscorlib?
IronPython can directly import only some of the .NET libraries — the most commonly used ones. To use additional .NET assemblies, they must be explicitly referenced. To add a reference to a .NET assembly, use one of the clr.AddReference* functions. See IronPython Tutorial for good examples and instruction on how to do this (if you’re reading the FAQ on the web, the tutorial.htm document is in the tutorial directory where you installed IronPython).