MySQL founder and developer Monty Widenius announced on his blog that the MySQL relational database management system would no longer be a free software project and will instead be under an Open Core model. Widenius pointed to an Oracle announcement last week, which detailed new commercial extensions for MySQL Enterprise Edition.
MySQL AB, the open source software company that created MySQL, was acquired by Sun Microsystems in 2008, which was then acquired by Oracle Corporation in 2010. Clearly Widenius is not pleased with Oracle's decision. “This is inconsistent to the original MySQL business model,” Widenius says. “The main strength of MySQL has always been that all MySQL source code was freely available,” Widenius says, adding, “It was thanks to this that MySQL got widely adopted and got to be used by tens of millions of users.”
In his blog post, Widenius says that an Open Core project has nothing to do with an open source project. Open Core models are also referred to as proprietary relicensing. Bradley M. Kuhn, Executive Director of the Software Freedom Conservancy, describes Open Core as “... a business model whereby some middleware-ish system is released by a single, for-profit entity copyright holder, who requires copyright-assigned changes back to the company, and that company sells proprietary add-ons and applications that use the framework.”
Widenius says that if a project depends on a single closed-source component, then the entire project should be considered closed source because it is reliant on one vendor for bug fixes, product improvement, and extensions or plug-ins that access internal parts of the product. He also points out that an Open Core project doesn't have the advantage of being tested by the open source community for bugs or security issues.
But Widenius also looks at the bright side. “What is interesting with the new commercial features is that parts of them where not developed by Oracle. The thread pool was originally developed by Ebay for MySQL 5.0 and contributed to MySQL to be include in MySQL 5.1,” he says. The improved thread pool can be duplicated in Widenius' new project, MariaDB 5.5, which is an open and free branch of the MySQL database server. MariaDB is a community-developed project sponsored by Monty Program AB.