rsh, rlogin, rcp question

we use the rsh stuff quite a lot here in our local network.
it is sectioned off from the outside and a cracker could
probably do us a lot of damage if they got in through our
fire wall or were a disgruntled employee or some such
but as for right now we are dependent on them for lots
of scripts and such.

to the question. We have a mix of SCO, HP-UX, and
Linux here, mostly SCO of which we use rcmd for
remote execution of commands. This does not exist
in Linux and I was wondering what the equivalent would
be. basically just execute a command remotely and have the
output displayed local.

any help would be great.

Thanks
Bill Warner