[[NealWalfield]] and [[MarcusBrinkmann]] wrote a paper titled
"[A Critique of the GNU Hurd Multi-Server Operating System](http://walfield.org/papers/200707-walfield-critique-of-the-GNU-Hurd.pdf)."
This was published in ACM SIGOPS Operating Systems Review in
July 2007.  This is sometimes referred to as "the critique."

The paper provides a technical overview of the Hurd's
architecture and critiques some of the decisions made.