The New Adventure Shell is a script that turns your shell into a text adventure game. It ought to pose as little restrictions on normal shell use as possible, and allow as many adventure commands as possible. Written for maximum portability.
Checkout - a simple file checkout script for the korn shell. This script makes it so that only one person can edit a source file at a time. Supports file history and a login system. Should also work in bash if you change the first line in the script.