The word "mux" is reserved in the Hurd terminology to mean invoking user specific translators based on the filename, which is what usermux and hostmux do. While, hostmux invokes a translator based on the host name, usermux invokes a translator based on the user name. You should be able to use usermux with nfs.

irc log 2010-08-25

<ArneBab> does that mean you could very easily use nfs to
          automatically mount the home folders of users by just
          accessing them?
<youpi> that's usermux, yes
<giselher> I am confused where is the difference ?
<youpi> usermux is specialized in user names
<youpi> i.e. it can translate it into a uid before giving it as
        parameter to the underlying translator, for instance
<ArneBab> what I meant is a little different, I think:
<ArneBab> each user has his/her own computer with the disk
<ArneBab> and all can access each others  folders as if they were local
<youpi> that could be done too
<youpi> it's a bit like autofs on linux
<giselher> settrans -ca nfs: /hurd/usermux /hurd/nfs server && cd nfs:/puplic
<giselher> ^-- is that right?
<ArneBab> youpi: but it can be done by anyone, not just root.
<youpi> ArneBab: sure
<youpi> giselher: I guess so
<ArneBab> and that is a huge difference. It lowers a barrier,
hopefully to such an extend that many more users can utilize it.
<anatoly> but it'll distinguish different computers?
<ArneBab> once the hurd has many more users, that is :)
<anatoly> s/but/but how
<youpi> anatoly: by a level of directories
<anatoly> cd nfs:/foo.bar:/blabla - it's how it should be?