There are many reasons for it, but in bottom line in open source you should look for the community.
MySQL CE, MariaDB or Percona DB?
Well, everyone should make their own decisions. However, you should decide if you are looking for commercial support or community support. If you are looking for commercial support, choose the company that you most trust (and gives you the best deal).
If you are looking for community support take a look where community is, check if the forums are active and if bugs that are being reported by the community are being taken care of. Finally search on Linkedin. It's a great way to sense where the wind blows.
What Should You Expect?
Faster releases, better response to community, some performance boost and in the bottom line: no change is need from your client side.
Migration currently is very simple, just like upgrading to a new major MySQL release:
sudo service mysql stop sudo cp -R /var/lib/mysql /var/lib/mysql.old sudo cp -R /etc/mysql/my.cnf /etc/mysql/my.cnf.old
- Uninstall MySQL
dpkg --get-selections | grep -v deinstall | grep -i mysql sudo apt-get purge -y percona-toolkit sudo apt-get purge -y php5-mysql sudo apt-get purge -y libmysqlclient18 mysql-client mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server mysql-server-5.5 mysql-server-core-5.5
- Install MariaDB
sudo apt-get install software-properties-common sudo apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xcbcb082a1bb943db sudo add-apt-repository 'deb http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.0/ubuntu trusty main' sudo apt-get -y update sudo apt-get -y dist-upgrade sudo apt-get install mariadb-server mariadb-client percona-toolkit
- Select your root password
sudo mysql_upgrade -uroot -p
Migration is easier then you may expect, now you can test and verify if it fits your needs.