Percona Vs. MySQL - Accelerating Database Performance - What Goes Behind The Scenes?

I've been reading a lot of Percona, which seems to be a drop replacement for MySQL and offers a lot of performance gains as compared to MySQL. Check out these graphs that show the performance of Percona Vs. MySQL: #-Link-Snipped-# .

Curious to know if anyone here's had a chance to play with Percona. I'm curious to know what makes Percona faster and more efficient in handling the databases?