Classic Traveller never died they just quit publishing books for it.
JTAS is still going strong and publishing material for it...and it's other incarnations.
In Fact I am part of a group that has been playing for 25+yrs in the same campaign. we have gone through retirements/deaths and the universe has grown.
Course we still play an occasional game of 1st ed AD&D as well but nothing is currently being published or kept up with that addition especially since 3rd ed came out.
Alternity is still a good system too. I have friends that still play that in the same campaign also. One friend loves that game better than anything else.
Traveller is still the grand champion in my opinion because of this longevity a devotion to the original rules. What other game published the original rules all in book form like traveller just did? That shows that there was somekind of following or they wouldn't have done it. Many of those old books are near impossible to find now except in the new reprints.
The difference here is that D&D never "died" - the people in charge just thought it was time for a new edition. That's also why I was uncertain about counting CT->Megatraveller as a death for Traveller.
Thanks for saying this-----
I hope this helps clear it up for you a little bit. Even D&D is not still publishing materials for old rules sets. Classic Traveller is still doing that despite the fact that:
1) GDW went out of business
2) There have been newer versions of the rules published.
3) The license was sold to other companies for publication.
These things are werein the difference is most apperent to me.