Download
The software can be downloaded from this link.
Installation and use
ITA doesn't need installation, you just have uncompress the downloaded file. Most of the decompressors (such as WinRAR on Windows) can do it with no problems. Before using it, you need Python installed.
On Windows
Download the last Python version from the oficial web page. There are some issues with Windows Vista and the version 2.6 if it is not installed as administrator, so in these cases I recommend to use the version 2.5.2.
Once installed, you just have to double-click the file ita.py.
On GNU/Linux
Almost all the distributions come with a default Python installation, so you shouldn't worry about it.
On the other hand, you may need the Tk libreries for Python. On Ubuntu, you can install it using Synaptic, searching the package python-tk.
The you just have to execute from a terminal the command: python ita.py.