From the back of the box:
The complete original print run of Challenge Magazine, scanned from the original copies in the GDW Game Designers Workshop reference library.
Includes Issue 25 (the first in the series) through Issue 77 (the last published). Plus the forecast Table of Contents for issue 78 (although those articles we're never published), and a comprehensive index of Challenge Magazine and its pre-decessor magazine Journal of the Travellers Aid Society.
Challenge Magazine included article coverage for all of GDW's role-playing games: Traveller, Twilight: 2000, 2300 AD, Space: 1889, Cadillacs and Dinosaurs, Dark Conspiracy, and Dangerous Journeys, plus other non-GDW game systems.