Neal Walfield and Marcus Brinkmann wrote a paper titled A Critique of the GNU Hurd Multi-server Operating System. 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.
IRC, freenode, #hurd, 2014-02-06
<bwright> Just read a paper on hurd. <bwright> Some interesting dot-dot and chroot issues were raised. <bwright> But this was written my guess is in about 2007.
IRC, freenode, #hurd, 2014-02-08
<antrik> bwright: both the dot-dot and chroot issues are fairly easy to solve... of course they do indicate some more fundamental things to keep in mind though. in fact, a few years ago we came up with a concept for making filesystem permission handling more robust... but nobody ever got to implementing it :-( <antrik> bwright: this paper, I guess you are referring to the "critique"? it was in fact written by the Hurd/L4 initiators. the observations made in this paper are right, but IMHO they got carried away on the conclusions -- most of the issues can be solved within the existing framework, if you think about the actual problems seriously <azeem> so they didn't think about it seriously? <antrik> azeem: not in the right mindset I'd say :-) <antrik> macrus actually said himself a while later that he probably could/should have implemented some of the ideas within the existing Hurd...