Welcome to the Virtual Object System. This document explains how to build the system from source in a Unix-like environment. It also describes ways to configure the behavior of the VOS library using environment variables, and how to use VOS behind a firewall. Please note that as of version 0.9.0, VOS has been split into a number of seperate modules, some of which depend on each other. The web page where you downloaded the packages should explain the dependencies.
You're likely most interested in Ter'Angreal, the VOS-based 3D multiuser chat browser. This application is found in the directory vos/3D/terangeral.
The webpage is http://www.interreality.org, look there for new versions, documentation, mailing lists, etc.