A VirtualPrivateNetwork is a private network connecting (some of its) nodes by tunneling traffic over a public network. Alternatively, if you have far too much money, instead of tunneling, you can use a dedicated data circut provided by your TelCo. Most VPNs only tunnel a single connection between two end points that serve to merge two LANs.

The MetaNet is an uncommon VPN, in that it is multipoint, and doesn't do encryption, authentication, or compression.

Why not? Those things sound kinda useful -- CraigBox

Simple answer: too difficult to code :) more important getting the easy bit going first. Also encryption/compression could very easily overwhelm some people's gateway boxen -- PerryLorier