ftp://ftp.in2p3.fr/pub/FreeBSD/branches/4.0-stable/src/sys/miscfs/  direct

[DIR]union/  direct  613+ twin directories
[DIR]umapfs/  direct  534+ twin directories
[DIR]specfs/  direct  290+ twin directories
[DIR]procfs/  direct  712+ twin directories
[DIR]portal/  direct  898+ twin directories
[DIR]nullfs/  direct  547+ twin directories
[DIR]kernfs/  direct  437+ twin directories
[DIR]fifofs/  direct  339+ twin directories
[DIR]fdesc/  direct  456+ twin directories
[DIR]devfs/  direct  2293+ twin directories
[DIR]deadfs/  direct  262+ twin directories
[DIR]CVS/  direct  65535+ twin directories