Running Linux programs
From FreeBSDwiki
enable linux compatibility -- you can do this via sysinstall if you didn't do it on your initial install.
add the following line to your /etc/fstab:
linprocfs /compat/linux/proc linprocfs rw 0 0
to run linprocfs -- you may need to do this:
rlyeh# kldload linprocfs rlyeh# mount /compat/linux/proc
See also Installing Linux Programs