T20 is ours from the start (Hunter's, with me jumping aboard waving my non-specific one-handed cut and thrust sword (see recent TML discussion for enlightenment!) some time later.
Before T20, I did (and still do) a lot of work on GURPS Traveller (I was in at the start and wrote the first 2 supplement s+ a small fragment of the rulebook)
I have been developing the TNE setting since GDW went down, at first for fun and then in an "official" capacity.
Also did some stuff for T4, but not a great deal. Never published anything for MT or CT. Although I was involved with games magazines since 1984, I first started writing Traveller for publicaiton in the 1990s.
Been playing the game 20 years, and writing for it that long....