update : 23/12/2020 MySQL

MySQL is a fast, robust RDBMS, deployed especially in Internet environments. MySQL was created by Michael “Monty” Widenius in 1995.

Initially focusing primarily on speed and simplicity, MySQL has gradually adopted new functionalities reserved for traditional "corporate" databases. MySQL supports transactions, referential integrity, stored procedures, triggers, asynchronous replication, clustering and data recovery in the event of a system failure.
MySQL uses the GPL and comes with exception linking, which enables the use of client libraries in programmes not compatible with the GPL. An Enterprise edition is also available, providing a number of graphics tools and support from its vendor company, Oracle. MySQL is widely used at companies the likes of Google and Facebook, and by major websites like Wikipedia.
MySQL is developed in C and C++ and can run on a very broad range of platforms, whether UNIX (Linux, Solaris, BSD, etc.) or Windows based.