Bukkit

http://dev.bukkit.org/server-mods/infiniteplots/

An epic Minecraft Bukkit world generator

Essentials tools in GUI --- 3️⃣0️⃣0️⃣ ACTIVE SERVERS ---

Hoth generator

Minecraft beta 1.7 terrain generator for bukkit.

MagicLoot

A hunger games server mod designed for use with the Hunger Games Map Generator.

An Automated Hunger Games plugin!

A world modification plugin for Magic

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

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

Create templeworlds that can be instanced and played by your players. Perfect for Adventure maps!

1.5.1 compatible SkyGrid mod based off of SethBling's idea.

A plugin to implements guilds and dungeons.

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

Giant Caves is a bukkit mod that creates giant underground caves in the world.

Generate world structures manually (villages, strongholds, temples, etc.)

Double the depth of your world

Infinite Floating Island Generator

AdventWorld supplies multiple world configuration ideal for multiplayer adventure maps/servers.