DOORS are one of the services that a Sysop does to enhance
his BBS system for you the caller. A door is a separate program
that is run outside of the BBS system. When you request a Door the
BBS system will normally shell out to give up ram memory so the new
program can be run. Doors are specially written code to allow you
the caller to control the game or interaction from your terminal.
Doors can be for games _ information _ or almost any thing that can
be run as a program. Most Sysops have security of some sorts
on there different doors. Your security level determines what doors
you have access to. Some Menu selections such as Call Back Verifiers
and Tomcat are also Doors that are selected not from a Door Menu but
from the BBS Menus themselves.