@my_actual_brain MySQL was owned by Sun but developed mostly by "volunteers" (people who contribute to MySQL without receiving any compensation from Sun).
Oracle bought Sun in 2010 and pissed off all the volunteers (including the original creator of MySQL). The volunteers kept working on it, but stopped sharing their work with Oracle and called it MariaDB.
When you see "MySQL", mentally substitute "versions of MariaDB from 15+ years ago". It's a mature tech, so mostly still relevant… but dated