Java Edition 15w34a

15w34a is the tenth snapshot released for 1.9.

Additions

 * NBT tags
 * Added  and   Byte tags to   tile entity.
 * (Integer) and  (List/Double) added to.
 * Added  String tag inside   for the   tile entity.
 * Added  byte tag to   tile entity.

Changes

 * Combat
 * New attack speed combat mechanic.
 * A meter shows up after switching items or attacking depending on the new attack indicator option in video settings.
 * Damage done depends on the fullness of the meter.
 * Fills in 0.25s for non-weapons, 0.8s for swords, pickaxes, and shovels, and 1.2s for axes.
 * Can be displayed next to the hotbar (left or right based on the player's main hand), under the crosshair or turned off.
 * Delay when selecting a sword, pickaxe, axe or shovel into the main hand.
 * Maps
 * Now start at a wider zoom level (1:4 instead of 1:1).
 * New recipe for zooming in on a map: craft shears and a map together in any shape.
 * Zooms in on the lower-right quadrant of the original map.
 * Command blocks
 * Contraptions from earlier versions will still work.
 * New textures that now vary depending on what direction they are placed, similar to logs and pistons.
 * 3 modes: impulse, chain, and repeat - color changes based on mode.
 * Impulse mode (orange): Command is run on rising edge.
 * Same behavior and color as previous versions.
 * Chain mode (green): Command is run whenever a command block pointing into this command block executes while this command block is powered - chain signal is forwarded even through disabled chain command blocks.
 * Repeat mode (blue): Command is run every game tick while powered.
 * Each new mode has its own block id and is obtainable with /give and pickblock.
 * Animated texture: The colored pixels in the middle change color.
 * Poweredness is now a data tag, allowing command blocks to stay enabled without needing redstone blocks next to them.
 * Minecarts with command blocks
 * Uses previous command block functions - no chain or repeat mode. However all commands before still work.
 * Because of this, there is no texture for the command block in the minecart and the block is just black.
 * Done button is available even when the command line is empty.
 * Zombies and zombie pigmen
 * Now lift their arms when becoming hostile.
 * Giants
 * No longer renders the model.
 * Still can be summoned using commands.
 * NBT tags
 * for  tile entity has been deprecated.
 * Optimizations
 * Optimized mob AI, path finding and block ticking.
 * 15% tick speed increase on 16 render distance.