Rrshd - another borrowing from DIET-PC - is useful as a secure (ironically!)
remote triggering system.  TLXOS uses it, along with an rsh_conntrack netfilter
kernel driver allowing use through firewalls, as a means by which a remote
machine can trigger the local launch of a specific pre-approved application,
via the obsolete RSH protocol.

Typically, the sort of thing you'd use this for is almost-seamlessly displaying
a local X11 application on a remote (e.g. RDP) desktop.

In addition to the /usr/local/sbin/in.rrshd binary, you'll need to create an
/etc/rrsh.allow file that contains the authorized commands (fully qualified
pathnames), and add a startup hook (in /etc/tlxinit on TLXOS Wheezy, or using
the provided rrsh.service systemd file on Jessie).