Bukkit

Allows chunk claiming using special terrain blocks.

CrazyGeo

Rebuild your arena in one click!

Lightweight plugin for managing per-world spawn points and more.

A Plugin to Control Weather and Time with Simple Commands

This plugin allows you to change your game mode with ease

An entity and memory cleanup utility plugin for Bukkit

A chunk pregeneration plugin for Spigot (and paper) servers.

Multiworld-Manager/-Teleporter

Simply unrestricts the placement of items and blocks. This is great for both creative and non-creative servers!

Set your server spawn as a superior

BorderVisualizer

This plugin adds many useful comands.

Being spammed with chunk errors? Try out this plugin on the chunk you are having an issue with!

A lightweight web administration that is easy to setup and fast to install

An add-on for Chunky which lets you create and manage world borders

FancyWorld

Bukkit 1.2.5-R1.0 Version 1.0 Anti-bedrock will solve your creative pests!

The easiest way to backup and restore your server, with in-game commands.

Will slowly (or quite fast) regenerate damaged terrain across the world.