Most of the code is in Python and IDL. The raw data files that the code runs on (consensus classifications for the site) are several hundred MB each, and are not hosted here. Contact the authors if you are interested in getting access to them.
If you have a GitHub account, you should be able to download the code and the data release paper (Willett et al., 2013, MNRAS accepted) from this site. Use the following command:
$ git clone https://github.com/willettk/galaxyzoo2.git
Or, if you want to make changes to the code/contribute to future papers via git (which would be really cool), you can fork it:
First, click the "Fork" button on https://github.com/willettk/galaxyzoo2. Next:
$ cd your_directory $ git clone https://github.com/your_username/galaxyzoo2.git $ git remote add upstream https://github.com/willettk/galaxyzoo2.git $ git pull upstream
Make some changes to the draft:
$ vim galaxyzoo2/datapaper/gz2datarelease.tex
Finally, go back to your GitHub page and switch to the branch you've been working on. Click the "Pull Request" button, add a title (eg, "Added reference to 1926 Hubble paper") and hit "Send". If we agree on the changes, I'll accept them and they'll be automatically merged into the upstream repository (ie, the master draft).
Much of the general Galaxy Zoo code is also available at the Zooniverse repo (@zooniverse).