Roblox is a MUD: The history of MUDs, virtual worlds and MMORPGs
MUDs are what got me into programming. I was obsessed with them as a kid, although they were associated with DnD which was considered satanic so I had to hide them from my parents and teachers, who both forbid me from associating with DnD or MUDs.Besides playing them, I actually spent more time as a "builder" than a "coder", which was an intermediate step in the hierarchy. As a builder, I would write hundreds of room descriptions, which most people never read. I desperately wanted to be a coder, the highest level of coolness in the MUD hierarchy, thus the journey began.However, to me, MUDs always had an underground sensibility to them that something like WoW or Roblox will never replicate. The lack of polish is part of the fun, in the same way an underground punk rock show might be more fun than Coachella. I'm not sure if there's any experience like it left on the internet,  I've never played Minecraft, but based on what I've read, that may come the closest.