if you plan to open Minetest server (or to play and spend your time creating worlds in general) and expect to experience something close to Minecraft - please, please DO NOT USE Mineclone5 instead of Mineclone2.
At some point some folks made a fork of mcl2 and added their fixes/improvements, it was called "Mineclone5", and for a few months the game really had more close features to the latest Minecraft: Java Edition version compared to the Mineclone2. For example, inner skin editor (in mineclone2 you only could change gender at the time).
As of right now, that's not relevant anymore. The project seems abandoned (of course, I could be wrong, but...), mineclone2 has more commits, newer items (for example, Lightning Rod, which mcl5 lacks). Mineclone5 now has a pretty buggy world generation, when it comes to the nether. You will have a hard time finding nether fortress (if you even can), in fact, you will have a hard time finding any life whatsoever, the place feels empty, which is not the case in mcl2.
I had to rebuild a lot of stuff cause of me trusting a bigger number and their game description in order to move from mcl5 to mcl2 on my private server for friends. Do not repeat my mistake.