The electronic MT Imperial Encyclopedia is a great purchase and updated the soft cover copy I have the book.

This is my favorite MegaTraveller product for introducing people to the game. Which is why I own 4 dead tree copies... It combines the Library data, equipment catalogue, and the Travel Flowcharts, plus the full UWP list for the Spinward Marches. It's one of three core rulebooks for Megatraveller. Having the PDF, however, has allowed easier use. I've hardly cracked the dead tree copies since getting the PDF.

Provides solid background to the MegaTraveller Universe.

Some one needs to spell check the introduction. After reading that I don't even want to look at the book.