MineOS.jar is a release file of the Minecraft mod biomes according to Simon, made for Minecraft 1.16.5. It was published on July 5, 2021 and is 0.1 MB in size. For the full description, screenshots and every other version, visit the biomes according to Simon mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
