I'm currently working on a closed-source commercial web-project which uses MariaDB as the database. I wonder about the licensing of MariaDB. Do we have to get a license to use it with our commercial project? On the website, they mention the "GNU General Public License, version 2". What means that exactly?
The GPL (GNU General Public License) states that you can use the software free of charge, but you cannot modify and sell it unless you release the source code. This means you can use it in your closed-source project.
MySQL was originally under the GPL, but has some different licensing issues since it was bought up by Oracle. You may still use it under the GPL, but Oracle also offers commercial licenses.