There are few pre-requisites.
  1. Python
  2. wxPython
  3. SciPy and NumPy
  4. Matplotlib
Python 2.5 is recommended - some early development was done on Dapper (thus python 2.4), so the whole thing may still be compatible, but I can't be sure. Make sure that all the other dependencies you get are for python 2.5. Once all the pre-requisites are installed, get the latest version of pyITC from sourceforge:

Download pyITC

To install, untar somewhere

tar xvzf pyitc-X.XX.tar.gz

go to the newly created folder

cd pyitc-X.XX

and install as root

sudo ./ install

There is also Windows installer (I haven't tried it yet). I usually say something like "if you feel like wasting your time with microsoft products...", but this time there is a reason to have windows installer, since the instrument control software does not run on linux.
I tested it on Ubuntu 8.04 (Hardy Heron) and (reluctantly) Windows XP. In theory, the whole thing should be platform-independent. It looks a little odd in xp (some controls have strange sizes), which is probably related to my original reluctance (long gone by now) to use sizers. GUI was created using Boa Constructor, and I have moved on to wxGlade, so I will probably rebuild it at some point and tidy up the code.