Bukkit

Vault is a Economy/Permission plugin for hooking into the various Economy and Permission plugins.

WorldEdit is an in-game map editor for both creative and survival

WorldGuard

PermissionsEx

A collection of useful commands and features for server admins and players.

Create modern-looking holograms in Minecraft.

A new perfect way to clear common lagg in your server!

The Bukkit World Management Plugin.

NPCs for Bukkit

The most used authentication plugin for Spigot and CraftBukkit!

EssentialsX

Plugin Manager For Bukkit

Set up custom villager shopkeepers

Mine spawners with silk touch

A simple to use and powerful plugin to create user interfaces.

Dynamic web-based maps of your Bukkit/Spigot server

CS-CoreLib

Allows server admins to easily modify how Minecraft works without programming anything

Tablist

Creates images and pixel-art using in-game blocks