These are cookies that we use to help make the site work in the way that we want you to experience it.
Drupal SessionId cookies - these are default session cookies used by the CMS that runs the website for user authentication. It is placed automatically when you visit the site and is removed when you leave. It doesn't send any data about you to anyone.
These are cookies that we use to see how people use the site and which pages they look at. We use this information to see how things are working and update and improve the site accordingly.
_utma, _utmc, _utmb, _utmz - these cookies are used by the Google Analytics service we use to see which pages and parts of the site you visit and anonymously send these results to them. They do send data out but you cannot be identified from it.
Other people's cookies
We don't currently use anyone else's cookies on our site.