I would like to use NLTK (Natural Language Toolkit) for Python using IronPython and call from an exisiting WPF/c# project.
Is it possible to reference NLTK from within WPF in this way.  For example to use Named Entity Recognition from NTLK?
Any advice or guidance appreciated.
It definitely is possible, as long as NLTK doesn't use any C extensions. It will be much easier if you use VS2010 though, because of the dynamic keyword. Look at the Microsoft.Scripting.Hosting library from IronPython, it will get you started towards loading the NLTK code and executing methods on it.
NLTK in IronPython from WPF