Bukkit

The multiworld plugin made by ferrybig

Creates cleanroom-style flat world generator with fully customizable layers. It can also be used to create empty space maps!

Pre-generates chunks, quickly, efficiently, and safely

Nothing but void!

PlotSquared

A Skyblock Plugin

Provides automated plots with protection (MultiWorld support)

Exotic Garden

This plugin allow full control of normal world generator

CityWorld

A simple void world generator.

uSkyBlock

IslandWorld - Survive on small isle

An epic Minecraft Bukkit world generator

An Automated Hunger Games plugin!

Create massive trees in Minecraft! Choose your own sizes and block types!

A plugin for Bukkit based Minecraft server that adds a floating island dimension similar to the old skylands.

IslandCraft modifies the terrain generation to create an ocean with many islands; each island is a single biome.

Survival in a sea of acid - like skyblock but with boats!

Its a plugin, but its mod-like: New mechanics, new worlds, custom bows and strucutres, faster game, survival reinvented.