MySQL community edition has a bad reputation for not performing well enough for enterprise level usage. This is why originally a lot of open source shops jumped ship for postgres. The Percona team has made a significant series of changes to the InnoDB storage engine which they package as a drop-in replacement called Percona XtraDB. You can find an itemized list list of changes on their website. Many of these are optimizations for performance. You can also see a recent performance comparison on their website here.
This collective boost of performance is what makes it so appealing to me. Percona’s devotion to open source is absolutely fantastic. All of their software is completely open source and they make all of their profit through training, support, and consulting. The company I work for has a Gold support contract with them. I have been using this support rather often lately and they have provided us with top notch responses. I have applied several of their suggestions, tips, and tricks to my daily efforts on various projects and it has had a noticeably positive impact on results.
They also have several added value pieces I use pretty much every day, including:
If you are interested in learning more about Percona and high performance MySQL you can find a sea of information at the following links.