Sponge Vanilla and Sponge Forge are now availables in Auto-Install on your Minecraft Unlimited and Minecraft Start
Sponge bring a new plugins API wich provide plugins for Vanilla servers (Sponge Vanilla) or Forge modded servers (Sponge Forge)
Sponge plugins are not the same as Bukkit (CraftBukkit, Spigot) plugins, so you need to use Sponge plugins availables on their official website : > Plugins List <