Semi-analytic galaxy catalogues based on the models of
Bower et al. (2006) and
De Lucia & Blaizot (2007) are available in the form of a database which can be accessed by submitting SQL queries over the web. Access to the full dataset requires registration. However, there is a smaller version of the database based on the "Milli-millennium" simulation. This uses exactly the same physical model and parameters as the Millennium simulation but it has a smaller volume and can be used without registration.
Mirrors of the database exist at two sites:
The Millennium Simulation