Licensing
About two months after Oracle bought MySQL, they announced a plan that divided the development into two camps. There would now be a MySQL community edition and a professional version. The community edition would no longer gain any new features, and the professional version would become a commercial product.
There was a vast and thunderous sucking sound in the open source community, as they thrashed wildly about to find a new platform for Free and Open Source (FOSS) development.
Oracle immediately (in about 2 weeks) countermanded the order, and declared that things would stay as they were for the indefinite future. Those with short memories, forgiving hearts, or who just weren't paying attention went on about their business. Many other open source projects either switched to PostgreSQL or suddenly grew PostgreSQL database support.
Today we have MySQL and MySQL Enterprise Edition. If you want "backup, high availability, enterprise scalability, and the MySQL Enterprise monitor", you...