The title of MySQL’s website states that they are the world’s most popular open-source database. This is false; MySQL is not an open-source database. That assertion is a fact, not an opinion.
MySQL is Free Software, licensed under the GNU GPL. People frequently use the two phrases “Free Software” and “Open Source Software” as synonyms, but there are very large, very important differences.
The difference between Free and Open Source
Open Source is much more of a development methodology than a philosophical standpoint. The first thing on the Open Source Initiative’s website is this introduction:
Open source is a development method for software that harnesses the power of distributed peer review and transparency of …[Read more]