-NB that this is a very bare set of installation instructions ! It
-describes a `default' configuration; you can do more esoteric things
-if you wish.
+This directory contains:
+
+* A userv service (`ipif') for allowing users to create network
+interfaces and handle the traffic for them. For instructions, see the
+comment at the top of service.c.
+
+* A VPN tunnelling system based on that userv service, which does
+encryption and can be used to join two networks. It uses its own
+nonstandard protocols, not IPSEC. Key setup is done via an ssh
+connection. For installation instructions, read this file.
+
+These tools have only been tested on GNU/Linux, and the ipif service
+in particular uses the Linux-specific `slattach' utility.
+
+NB that this is a very bare set of installation instructions for the
+VPN system ! It describes a fairly `default' configuration; you can
+do more esoteric things if you wish.