According to the Fair use clause of the FFE license, commercial Traveller derivative works (actual rewrites of copyrighted rulebooks)
FFE explains this are explained in part 3 of the Fair Use clause. (I guess you could add this the d20 Game System License and the OGL)
www.farfuture.net/FFEFairUsePolicy2008.pdf
I think it is interesting that the SciFi20 documents are taken almost verbatim from the Traveller's Handbook (The T20 core rulebook). I think that, by ditching the Traveller name and all references to the specific "Traveller" T20 universe, the "author" of that book was hoping to resell parts of the book without making any new material. As I see it, the only available materials for the production of new gaming products (from any setting)are the items listed in the respective SRDs (system reference documents). In this case, that information is th the d20 3.0 SRD, but I still don't get it.
SciFi20 (Player's Handbook, Combat Manual, Design Manual and Planetology Guide) is just a reprint of chapters 1-7, 8, 12 and 16. I was a little miffed after I bought it because I already have the Traveller's Handbook and, besides some new art by Brian Gibson (which is very cool!), and a new page layout there's nothing there. Perhaps SciFi20 was not finished before it was released?
I'm sorry to gripe, but that was a $23 bundle product