From the introduction:
There are now other places to goto besides cyberia that are linked via. tunnels placed at various places in the walls of cyberia. These worlds have laws of thier own. The Virtual Excursions places are still there but have the same laws as cyberia. The outer worlds have laws all thier own. These worlds make up whats called The Web. The web is like a giant tinkertoy set where places are joined by lines/ tunnels to other places. Cyberia is still the starting place and center of all activity and the web itself. Most worlds are joined into the outside walls of cyberia at ground level. A few are placed elsewhere.
User summary:
Version IV is released as a "patch" document, in an archive containing all of the files from Virtual Virtual Reality (V3), plus the VVR Version IV" "patch" - intended to replace specific (relatively minor) portions of the rules.
The Version IV archive also includes a dice roller program, a simple character generator program, and support files to implement the game as a "text adventure" on a bulletin board system.