Bukkit

Version 15.0a notes:

• Fixed a bug where potion effect on-hit duration was in seconds rather than ticks.
• Removed the new gamerule lines.

Version 15.0 notes:

• Zombie world mode has been added! When enabled, it will instantly transform your config into a preconfigured zombie apocalypse, with no setup or downloads.
• To enable use: Automatically over-write relevant parts of config to zombie apocalypse for next run?: true
• You can now add potion effects to monsters dealing direct damage to players!
• Horses have been implemented.
• Mega-aggro was running at a very slow speed, monster speeds have been fixed. 2.0 speed is now VERY fast.
• You should no longer have silverfish spawn directly at players' feet when mega-aggro is enabled for pigzombies or spiders/cavespiders. You may still see them when mega-aggro is enabled for these mobs, disable it in advanced properties.
• Monsters which are building air bridges downwards will no longer suffocate players.
• Custom health has been updated to support 1.6.2.