Not only is it still going but it's possible to dust off your ancient account. An old guild mate reported that he had recovered his account originally closed ~2000. Sadly, of the two accounts I had back in the day the only one still recoverable was my alt/mule account. My original account was one of the, well, original accounts from opening day, so it's a shame it was lost.
But still, it was fun to run around with one of my guys for a couple of hours. One thing I thought was cool was there had been some custom content involving my guild added near the bank where my guild hung out. It was still there, all these years later!
Eq has of course had some major server merges but your old account will still be on both UO and EQ.
To me UO is a breath of fresh air after 20 years of trash games except for a stand out few. Seeing my old wood elf ranger with swift wind and lupine dagger still glowing was magical. Almost as magical as re-exploring kelethin.