Tor: The Errata Tor is one of the most popular deployed anonymity networks today, and provides privacy to people around the world. Since the Tor design paper was first published in 2004, however, the design has evolved considerably--sometimes to address vague parts of the original design, and sometimes in reaction to unforeseen interactions with reality. This talk will present a window into the evolution of a popular security software package, and describe some interesting unpublished challenges and solutions in the field of low-latency anonymous communications.