I started seriously playing Marathon back in '96 or '97, though I did know of its existence as early as '95. Since then I've created jjaro.net and Traxus , and I still actively update the former and passively maintain the latter.
I've been part of the development cycle for the two scenarios TGI and WMaiD -- I did, however, leave WMaiD long before its completion. I take a very active stance on AlephOne, and consider myself to be very up-to-date on the status of the project. I have contributed minor bits of code in the past, but I don't see myself writing anything major any time soon.
I also do a vast amount of things that are in no way related to Marathon.