The Biome Update

The Biome Update (aka The Update that Changed the World, or The World Generator Update), was a big update with the title 1.7. 1.7.2 was released on October 25, 2013, 1.7.1 on October 23, 2013 and 1.7.0 on October 22, 2013. There were 14 snapshots, from 13w36a  to 13w43a ; 13w36a, 13w36b , 13w37a , 13w37b , 13w38a , 13w38b , 13w38c , 13w39a , 13w39b , 13w41b , 13w42a , 13w42b , 14w43a.

Features
Biomes: Mesa, Mega Taiga, Roofed Forest, Birch Forest, Savanna, Extreme Hills+, Deep Ocean and non-snowy Taiga

Statistics: 20 new technical biomes, AMPLIFIED world type, New particles, 7 new commands, 6 new achievements, 4 new statistics,

Blocks: Acacia and Dark Oak wood, wood planks, slabs, stairs, stained glass, stained glass panes

Items: 3 new fish, new potion, 2 new enchanted books (for fishing rods), 10 new flowers