Short for Network File System, but there are others. Invented at Sun. Supports a large fraction of UNIX filesystem semantics (larger than the other networked FSes) but definitely not complete.
Tcl and NFS
One issue, at least up until 8.5a1, is that a fair number of tests in the core test suite fail when run in an NFS-mounted directory. This is because of the fact that NFS only supports a subset of the classic semantics.
LV On what platforms? Nearly all testing I have done since Tcl 6 has been done on NFS mounted directories - and I get less than 6 failures. Of course, I've been using SPARC SunOS machines.
DKF: I have problems persistently with (IIRC) both Sol9 and Linux. Perhaps it also depends on the configuration of the NFS server? If so, we've got a total imponderable and a set of tests that are simply non-portable. :^/