I think the people who have designed he current version of this site have done a terrific job, it looks great!
Much of the content seems to be based on Mediawiki, which I also have installed on a server to run a dictionary/encyclopedia about neuroscience and cognitive science. I run mine with the default monobook layout but would very much like to construct a custom header like the one this site uses. So now to my question, is this page header a homemade hack or is there some guide somewhere on the net of how to do it, or some code to download from anywhere?
Posts: 32509
codex.gallery2.org is mediawiki, gallery.menalto.com is drupal.
all themes are developed by the gallery 2 project (of course they are based on some other themes).
they are not available for download AFAIK. if you're interested in these themes, maybe send an email to the gallery-devel mailinglist.