From the Introduction:
NITHUS is a world adventure, APPROVED FOR USE WITH TRAVELLER. The planet is located in the Banderhue Quadrant, Theta Borealis Sector of the Imperium. It is inhabited by the Captutains, a peaceful, telepathic race. Throughout the following pages you will explore their colorful world, animals and violent past. The referee should feel free to add to or delete as he wishes.
NITHUS uses Basic Traveller with references to High Guard (2nd Edition), Mercenary, and 1001 Characters.
The setting is non-canon. Includes a large full color world hex map.