Bukkit

New features:

• Compatibility options
• More Fly-options
• Ability to save the old tabname in 'ChangeTabNames'
• Options to auto-reappear on quit/worldChange
• Options to prevent block-placing/block-breaking

Improvements:

• Better performance
• Code cleanup
• More configurable messages and placeholders

Changes:

• ProtocolLib is now optional (The serverlist features are disabled if there is no ProtocolLib on the server, but the rest still works.)
• Changed some methodes of the api and marked the old ones as deprecated, since I'll remove them in the next update

A little bug related to Essentials, v5.0.1 fixes it.