If you have not already done so, install Opus and UrbanSim, along with any needed supporting software, and download the sample data and configurations. Directions for the current version of the code are at http://www.urbansim.org/docs/installation/. This tutorial is for the development version of the code currently in the svn repository. It relies on the PyQt package to produce its graphical user interface. Earlier versions (4.1.2 and before) use an older user interface based on the Enthought Traits packages. If you are using a previous release rather than the current version fresh out of the subversion repository, the table of releases at http://www.urbansim.org/download/ includes a link to the tutorials and installation instructions corresponding to that particular version.