From the ‘Open Core is not Open Source’ files:
The open source MySQL database became the popular success that it is today, due to the fact that it is open source. MySQL is freely available and in the beginning, all of its features were too.
Things changed over the years, MySQL went corporate, there was an Enterprise Edition, dual licensing and oh yeah they were acquired by Sun and then Oracle.
Oracle recently released a number of commercial extensions to MySQL which the founder of MySQL, Monty Widenius isn’t too fond of. Then again, Monty wasn’t fond of commercial extensions at MySQL AB or under Sun either.
Monty’s issue isn’t about making money from open source, it’s about locking users into an open core model.
“What is most important to understand about an Open Core project is that it has nothing to do with an open source project,” Monty blogged. “If you are depending on a single closed source component then you have to regard the whole project as a closed source project as you lose all the benefits of open source.”
Monty added that at least one of the components that is now set to be a closed source module is a Thread pool feature that wasn’t originally 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,” Monty blogged. “Only the new scheduler interface code was added to MySQL 5.1 while the thread pool itself was added (but accidentally with a slower implementation) into MySQL 6.0. Oracle never back ported the thread pool code to the MySQL 5.5 community version and now also the MySQL 6.0 tree is deleted.”
That issue aside, the open source model does work, since Monty’s MariaDB (which is a fork of MySQL) has the same thread pool technology. Thanks to the open source licensing that is the core of MySQL, Monty has been able to build MariaDB as a fork providing choice to users.
Those that don’t want to pay Oracle have a choice. The core of MySQL remains free and Oracle does continue to build it out in a more aggressive manner than Sun ever did. Oracle was able to push out MySQL 5.5 and version 5.6 is now in preview.
If by some chance Oracle did move to strangle MySQL open source code, MariaDB is there and Monty is clearly ready to step in and reclaim leadership. Isn’t open source great?