Bukkit

BukkitCLI provides a simple way for plugins to execute commands on the command line and can be used as API.

MC Web

Report useful server information to your chat or console.

Gadgets from brawl stars

Allows UNLIMITED Player Slots on Your Minecraft 1.8 Server!

BeginnerAPI

Playing music in Minecraft with Texture Pack has never been easier

The GetOpt-like tool for Bukkit plugins.

An API for Bukkit plugin developers who want to easily create inventory menus

Computer plugin

A simple economy API with no money limit!

Allows users to maintain a friend list.

Levitate your bukkit commands and register them the easy way

Skript alternative that uses Java source files

Test your server to see if it is working!

Report server performance data and core event parameters to New Relic SaaS for analytics and graphing

Convert Custom CraftBook recipes to ChestCommand GUIs

Let your tablist have colors!

This is a tool for developers that makes it eaiser to design scoreboards

UnrealAPI