http://tttyx2vwp7ihml3vkhywwcizv6nbwrikpgeciy3qrow7l7muak2pnhad.onion/Summary.html
The
prototype included proxies for private Web browsing, remote login, and
also anonymizing versions of those proxies that remove identifying
information from the data stream. These pages describes the Onion
Routing system at several levels of abstraction, including a detailed
specification for reimplementors.