Frankly I have no use for the d20 system. It doesn't matter. This product is great anyway if only for having a world generation system that is quick, colourful, and focussed on the important thing, "What can this world be used for in a roleplaying game?" Having spend hours generating one worthless rock after another in orbit around one red dwarf after another or even one collection of generic Traveller stats after another, I appreciate that a great deal. Apart from that it has quite a good way of rolling large scale conflicts for those PCs who manage to put themselves in charge of military units, espionage agencies, or corporations. The alien creation stuff is interesting. They acknowledge that there are two basic approaches to alien psychology, making them something nearly impossible to communicate with, or make them basically humanlike, but with a Hat or two, a defining trait like "scholarly" or "treacherous". C'mon. You know it's how you do it. It's how Star Trek and Star Wars do it too. Example alien critters and the example set of worlds (on a Traveller subsector map) look like stuff you could totally snag for inspiration. This is definitely worth the download for any interstellar science fiction gm.
[5 of 5 Stars!]