Bukkit

Gives more world functionality

Warn your players and keep chat clean!

Manage refunds of player deaths

Beacon of Lightning

EasyTimedMessages allows for timed broadcasts (set in config) to be made easily.

Pesky users wanting op. Give them OPme

Worldguard GUI, User can buy Regions and manage easily

TheBroadcast

Gives a better reward for mining.

Automatically run minecraft commands!

Lets a player broadcast a command

Choose the versions with which players cannot connect (for ViaVersion)

DigammaVote

very basic server utilities

SimpleMaintenance

Ever wanted to tell your players if your staff is on duty? Then StaffOnDuty is for you!

TutorialSpawn allows the user to create a tutorial area for their server.

FakeChat

Restricts the end and nether for people without permission

Helps admins do everything they can to help players.