This is mine, Endless Online, which I played a lot in my early school years. Very simple, mostly just running around exploring things, killing enemies for random drop loot or gold and occasionally synthesizing those items to make cooler cosmetics or armor, while chatting with folks the whole time as the main focus.
And apparently the site is back up after some years being down, with players hosting servers? Maybe I'll check out a custom server sometime. https://www.endless-online.com/
Next they'll tell me that Asperetta or Illutia have resurfaced.