Minecraft: X02 is a new way to play Minecraft, it includes new stuff and has many versions.
MC: X02 Pre-release 1.0
MC: X02 Pre-release 1.0 is the first version of MC: X02, it adds new stuff like:
Go back to the time where there were no Creepers.
Added new desert structures which are rarely found.
Respawn In Hardcore
If you die in Hardcore, you respawn, but if you die more than three times, the world will be deleted.
Towers in the ocean made out of wood and fences; mobs will spawn and try to hurt you if you get close enough.
New use for Lapis Lazuli.
MC: X02 Pre-release 2.0
MC: X02 Pre-release 2.0 is the second version of MC: X02, it adds more things like:
New types of dungeons found underground in deserts, its made out of sandstone only, it has a Skeleton spawner in the middle and two chests which contain saddles, gunpowder, wooden swords and two wooden pickaxes.
Nether Creepers and Nethermen are new mobs found only in Hard or Hardcore difficulties.
Basically a new dimension.
MC: X02 Classic 1.0
MC: X02 Classic 1.0 is the first official release of MC: X02, it includes new stuff like:
New mobs found only in Hard or Hardcore difficulties.
A new item.
Creative / Survival Mix Mode
A mix of survival and creative, you can switch to survival mode by typing in the chat box 'survival' and you can switch to creative mode by writing in the chat box 'creative.'